Add guide to set a Gelato relay

[aguzmant103]

Similar to Add guide to set an OpenZeppelin relay#85 and after semaphore-protocol/boilerplate#44

Create a guide

[timou0911]

Hi @aguzmant103, @vplasencia! I'm interested in this Gelato issue and would like to request an assignment.

Could you clarify the remaining tasks? Thanks!

[NathaliaBarreiros]

Hi @aguzmant103, @vplasencia! I'm interested in this issue and would like to request assignment.

Could you clarify the remaining tasks for this issue? Any additional context would be appreciated. Thanks!

[cedoor]

@timou0911 @NathaliaBarreiros Do you want to work together or?

The boilerplate already supports Gelato. The idea here is to create a simple guide to explain devs how they can set their own relayer with Gelato.