expand ADR template (#5232)
expand ADR template (#5232)

## Description

These changes are up for discussion. 

The current ADR template leaves a lot of room for interpretation and we currently do not have implementation level specs. This change to the ADR template is meant to solve both of these pitfalls. 

Thank you to @tessr for providing an amazing template to follow. I only took a few things from it but we can add more if people would like more detail. 

Closes: #XXX


tendermint/tendermint,tendermint/tendermint,tendermint/tendermint,tendermint/tendermint