Converting system for release notes

[carver]

Are we happy with the towncrier-style release notes? If not, some alternatives popped up in #710, especially:

• https://crates.io/crates/release-plz
• https://github.com/Byron/gitoxide/tree/main/cargo-smart-release

They work best with Conventional Commits, which would require us to shift how we write commit messages. (probably for the better, but it still requires some discussion)

It's worth quickly checking if that would meet our needs better.

[njgheorghita]

In sync today, we agreed to replace towncrier with one of the above crate-based libraries

A loose and incomplete summary of steps a :flamingo: will need to take to perform the conversion, when we are ready to cut our first official "alpha release"

• [ ] Run towncrier once, to compile the existing newsfragments into a release note
• [ ] Remove all support for towncrier & related tooling
• [ ] Add support for a rust-native release notes library
• [ ] Make sure that the compiled newsfragments release notes (or at least the important parts) get included into the rust-native release systme
• [ ] Update the discord channel that commits now need to follow the conventional commit format.
• [ ] It seems like once we remove towncrier we can also remove the docs/ folder in this repo. But this should be verified before removing that directory.
• [ ] ...

[ogenev]

I think at this development stage, the simpler is better. Adding the rust-native release notes library seems unnecessary to me.. Using GitHub releases and manually updating Cargo.toml version may be good enough and simpler (check reth or lighthouse for inspiration).

Here is what release-plz can do for us:

• CHANGELOG generation (with git-cliff).
• Creation of GitHub/Gitea releases.
• Publishing to a cargo registry (crates.io by default).
• Version bumps in Cargo.toml.

I guess we care only for two things from this list above: the creation of GitHub releases and Cargo.toml update. Even at this stage, we don't update Cargo.toml when deploying to the testnet. We don't need to publish trin to crates.io, that's why I think this tool is more directed toward library releases, and introducing a CHANGELOG in the repo will complicate things (why reth and lighthouse don't have such a file? ).

Here is an example manual GitHub release only with a few clicks: https://github.com/ethereum/trin/releases/tag/testnet-v0.1.0-alpha.1.