Update documentation of CI checks

[vkucera]

• Contribution guidelines:
  • Give more details about what which CI check does.
• Recompilation instructions:
  • Add a tip on recompilation over the master build.
• Tools:
  • pre-commit hooks
    • Make the description of hooks more general.
    • Mention installation with pipx.
    • Add instructions for skipping hooks.
  • Clang-Tidy
    • Add a tip on running on a feature branch.
    • Add a warning about the full build.
    • Make instructions for O2Physics-code-check more explicit.
    • Fix link to naming conventions.
  • Include formatter
    • Update the execution instructions for the new Python script.
    • Mention option to run as a pre-commit hook.
  • O2 linter
    • Simplify execution instructions.
    • Mention option to run as a pre-commit hook.