Repo roadmap

[Amxx]

### Tasks
- [ ] Figure out licence
- [ ] Readme.md
- [x] Setup CI
- [x] Setup Linter
- [x] Setup Slither
- [x] Setup coverage
- [ ] Setup gas reporting
- [x] Branch protection
- [x] Changelog.md

[ernestognw]

Added Slither setup and branch protection.
For the case of the license and README, we may need to adjust details but I'd say it's already in a good state
We have coverage pending and gas reporting.

[ernestognw]

Added coverage too. I didn't configure Codecov yet since we'll need authorization from IT