Supplement the CONTRIBUTING.md file with additional guidance regarding the PR section

[kurosakishigure]

Page Link

https://github.com/kurosakishigure/katharsis/blob/canary/CONTRIBUTING.md

What is the documentation issue?

The document currently lacks a clear explanation of the strong alignment required between the content of PRs and their corresponding Issues. Sometimes, PRs may extend beyond the scope of what was originally outlined in the related Issue, introducing out-of-scope changes.

Additionally, if a PR is not of critical importance, we should encourage contributors to share their ideas in the Discussions section instead.

Is there any context that might help us understand?

Include these details in the introductory comments at the beginning of the document for clarity:

[kurosakishigure]

We also need to remind contributors that if they wish to elevate an idea to an Issue, they should use the "Create issue from discussion" feature to ensure it is properly linked to the corresponding Issue:

[kurosakishigure]

For the chore type, we have two ideas:

1. Inform contributors that this is a special type that typically skips the issue stage and goes directly to a PR submission.
2. Remove the description for this type, as it is primarily used for version bumps at this stage and isn't very relevant to contributors.

Additionally, we might need to clarify that some labels are reserved for bots.

[kurosakishigure]

We also need to add the purpose and precautions for using the "revert" tag.