Hash prefix in base64 excludes the "u" character that HoloHashB64 prepends

[mattyg]

What is incorrect

The base64 hash prefixes are correct, but missing the "u" character that HoloHashB64 expects.

This is explained in the rust docs page: https://docs.rs/hdi/latest/hdi/hash/index.html#self-identifying-hash-encoding

My suggestion is to include that rust docs page in the "References" section.

Link to page

https://developer.holochain.org/build/identifiers

[mattyg]

Actually this is covered in the rust docs, so I'd say its probably not necessary to expand upon here: https://docs.rs/hdi/latest/hdi/hash/index.html#self-identifying-hash-encoding

[mattyg]

Looks like that rust docs page is not linked to from this page, so reopening this issue and renaming to just link to that page.