Problem: outdated contribution guidelines

[tomtau]

The contribution guidelines aren't followed as described here: https://github.com/crypto-org-chain/cronos/blob/main/CONTRIBUTING.md#working-on-issues and there are some undocumented conventions, e.g. pull request opened with Feature: ... but there's no issue describing what problem that feature solves.

[tomtau]

For reference, see the rationale for the current contribution guidelines (and the original blogpost)