[bug]: clean up documentation for sendpayment

[ZZiigguurraatt]

The litcli ln sendpayment documentation is very rough and needs to be cleaned up. multi is misspelled in the name. Also, I don't know what options are really allowed or have just been copy/pasted over from the lnd sendpayment cli docs. It seems like there is a lot of extra stuff. Also, https://lightning.engineering/api-docs/api/taproot-assets/taproot-asset-channels/send-payment/index.html does not show that the CLI exists at all. Also, the documentation at https://lightning.engineering/api-docs/api/taproot-assets/taproot-asset-channels/send-payment/index.html seems to have different description text for fields than what you get when running litcli ln sendpayment -h.

Another thing that is very confusing is litcli ln payinvoice. The docs you get from litcli ln payinvoice -h don't make it clear what the difference is between sendpayment and payinvoice. With lnd, it is very clear that payinvoice is a shortcut for sendpayment --pay_req=

litd@dave:/$ litcliln sendpayment -h
NAME:
   litcli ln sendpayment - Send a payment over Lightning, potentially using a mulit-asset channel as the first hop

USAGE:
   litcli ln sendpayment [command options] dest amt payment_hash final_cltv_delta pay_addr | --pay_req=R [--pay_addr=H] --asset_id=X --asset_amount=Y [--rfq_peer_pubkey=Z]

CATEGORY:
   Payments

DESCRIPTION:
   
  Send a payment over Lightning. One can either specify the full
  parameters of the payment, or just use a payment request which encodes
  all the payment details.

  If payment isn't manually specified, then only a payment request needs
  to be passed using the --pay_req argument.

  If the payment *is* manually specified, then the following arguments
  need to be specified in order to complete the payment:

  For invoice with keysend,
      --dest=N --amt=A --final_cltv_delta=T --keysend
  For invoice without payment address:
      --dest=N --amt=A --payment_hash=H --final_cltv_delta=T
  For invoice with payment address:
      --dest=N --amt=A --payment_hash=H --final_cltv_delta=T --pay_addr=H
  
  To send an multi-asset LN payment to a single hop, the --asset_id=X
  argument should be used.

  Note that this will only work in concert with the --keysend argument.
  

OPTIONS:
   --pay_req value                 a zpay32 encoded payment request to fulfill
   --fee_limit value               maximum fee allowed in satoshis when sending the payment (default: 0)
   --fee_limit_percent value       percentage of the payment's amount used as the maximum fee allowed when sending the payment (default: 0)
   --timeout value                 the maximum amount of time we should spend trying to fulfill the payment, failing after the timeout has elapsed (default: 1m0s)
   --cltv_limit value              the maximum time lock that may be used for this payment (default: 0)
   --last_hop value                pubkey of the last hop (penultimate node in the path) to route through for this payment
   --outgoing_chan_id value        short channel id of the outgoing channel to use for the first hop of the payment; can be specified multiple times in the same command
   --force, -f                     will skip payment request confirmation
   --allow_self_payment            allow sending a circular payment to self
   --data value                    attach custom data to the payment. The required format is: <record_id>=<hex_value>,<record_id>=<hex_value>,.. For example: --data 3438382=0a21ff. Custom record ids start from 65536.
   --inflight_updates              if set, intermediate payment state updates will be displayed. Only valid in combination with --json.
   --max_parts value               the maximum number of partial payments that may be used (default: 16)
   --json                          if set, payment updates are printed as json messages. Set by default on Windows because table formatting is unsupported.
   --max_shard_size_sat value      the largest payment split that should be attempted if payment splitting is required to attempt a payment, specified in satoshis (default: 0)
   --max_shard_size_msat value     the largest payment split that should be attempted if payment splitting is required to attempt a payment, specified in milli-satoshis (default: 0)
   --amp                           if set to true, then AMP will be used to complete the payment
   --time_pref value               (optional) expresses time preference (range -1 to 1) (default: 0)
   --dest value, -d value          the compressed identity pubkey of the payment recipient
   --amt value, -a value           number of satoshis to send (default: 0)
   --payment_hash value, -r value  the hash to use within the payment's HTLC
   --final_cltv_delta value        the number of blocks the last hop has to reveal the preimage (default: 0)
   --pay_addr value                the payment address of the generated invoice
   --keysend                       will generate a pre-image and encode it in the sphinx packet, a dest must be set [experimental]
   --asset_id value                the asset ID of the asset to use when sending payments with assets
   --asset_amount value            the amount of the asset to send in the asset keysend payment (default: 0)
   --rfq_peer_pubkey value         (optional) the public key of the peer to ask for a quote when converting from assets to sats; must be set if there are multiple channels with the same asset ID present
   
litd@dave:/$ 
litd@dave:/$ 
litd@dave:/$ 
litd@dave:/$ litcliln payinvoice -h
NAME:
   litcli ln payinvoice - Pay an invoice over lightning using an asset.

USAGE:
   litcli ln payinvoice [command options] pay_req --asset_id=X

CATEGORY:
   Payments

DESCRIPTION:
   
  This command attempts to pay an invoice using an asset channel as the
  source of the payment. The asset ID of the channel must be specified
  using the --asset_id flag.
  

OPTIONS:
   --pay_req value              a zpay32 encoded payment request to fulfill
   --fee_limit value            maximum fee allowed in satoshis when sending the payment (default: 0)
   --fee_limit_percent value    percentage of the payment's amount used as the maximum fee allowed when sending the payment (default: 0)
   --timeout value              the maximum amount of time we should spend trying to fulfill the payment, failing after the timeout has elapsed (default: 1m0s)
   --cltv_limit value           the maximum time lock that may be used for this payment (default: 0)
   --last_hop value             pubkey of the last hop (penultimate node in the path) to route through for this payment
   --outgoing_chan_id value     short channel id of the outgoing channel to use for the first hop of the payment; can be specified multiple times in the same command
   --force, -f                  will skip payment request confirmation
   --allow_self_payment         allow sending a circular payment to self
   --data value                 attach custom data to the payment. The required format is: <record_id>=<hex_value>,<record_id>=<hex_value>,.. For example: --data 3438382=0a21ff. Custom record ids start from 65536.
   --inflight_updates           if set, intermediate payment state updates will be displayed. Only valid in combination with --json.
   --max_parts value            the maximum number of partial payments that may be used (default: 16)
   --json                       if set, payment updates are printed as json messages. Set by default on Windows because table formatting is unsupported.
   --max_shard_size_sat value   the largest payment split that should be attempted if payment splitting is required to attempt a payment, specified in satoshis (default: 0)
   --max_shard_size_msat value  the largest payment split that should be attempted if payment splitting is required to attempt a payment, specified in milli-satoshis (default: 0)
   --amp                        if set to true, then AMP will be used to complete the payment
   --time_pref value            (optional) expresses time preference (range -1 to 1) (default: 0)
   --amt value                  (optional) number of satoshis to fulfill the invoice (default: 0)
   --asset_id value             the asset ID of the asset to use when sending payments with assets
   --rfq_peer_pubkey value      (optional) the public key of the peer to ask for a quote when converting from assets to sats; must be set if there are multiple channels with the same asset ID present
   
litd@dave:/$ 
litd@dave:/$