Add a guide to the steps to be run in local before opening the PR.

[asnimansari]

Maybe it's good to list down to run the basic steps mentioned in the ci check so that a newcomer can ensure those checks are satisfied before committing.

Either the user can manually check this. Or we could add a git pre-commit or pre-push hook.
Pre commit hook might be a bit annoying as rust compilation takes time.

[elpiel]

Thanks for raising the issue.

As a first step we should add Contributing.md and add the steps there.

Steps for adding new sentences should also be extended with:

• the addition of adding a new feature
• adding the sentence to the all_sentences list
• documentation in lib.rs
• documentation in README.md

We should also update the README.md as it doesn't include all the steps currently