update documentation

[mustafasoylu]

After talking with some of our users, I wanted to update the documentation in several places.

1. Set a note explaining they don't have to install somesy to their PC or add it as a dependency if they use it as a pre-commit hook.
2. fix the version to the latest in the somesy.toml example
3. add a note to warn users of the latest version
4. explain why we set some fields as compulsory fields

When setting somesy up in the prototyping phase, we discussed the compulsory fields with Anton. It is not much, and a project should have at least that much metadata in its repository, else somesy doesn't mean anything anyway. However, we can discuss whether we should change the current compulsory fields.

Compulsory fields for project metadata:

• name
• description
• version
• license
• people: at least 1 person

Compulsory fields for project metadata:

• email
• family names
• given names