chore(changelog): add git-cliff configuration

[orhun]

Description of change

Add git-cliff configuration.

Changelog preview:

How has this been tested? (if applicable)

N/a

[oddgrd]

Thanks @orhun, this looks great! 🤩

I have two (non-blocking) questions since I'm not familiar with git-cliff yet:

• How will commits that don't match any of the regexes in commit_parsers be grouped?
• How is it determined which part of the codebase the commit belongs too (e.g. (gateway) <commit message>?

[orhun]

How will commits that don't match any of the regexes in commit_parsers be grouped?

If they are conventional, they will appear in their own section. For example, foo(bar): xyz will be:

### Foo
- (bar): xyz

If they are not conventional, they will be skipped. We can potentially set up git-cliff to utilize unconventional commits as well but the most of the codebase seems to be using conventional commits so I'd say there is no need for that. Conventional commits gud.

How is it determined which part of the codebase the commit belongs too (e.g. (gateway) <commit message>?

From the scope of the commit message, e.g. feat(gateway): <commit message>

[jonaro00]

Alright, so we'll have to make sure we modify names of commits when we squash them (if needed). Would be good to have non-matching ones get thrown into Misc. just in case.

[orhun]

Done in b3bd557

[oddgrd]

Perfect, thanks!