Introduce guide when RLS notes missing

[miroslavpojer]

Background

• Creating release notes (title and bullet list) requires manual effort or relies on PR templates. In both cases, the PR author needs to pay extra attention and follow a process that can be repetitive.
• To improve the developer experience and reduce time spent on boilerplate work, the action will offer two optional inputs to automate or assist with release notes creation.

Feature

Introduce two new inputs:

guide

• Required: No

• Default: true

• Description:
  When enabled and no "Release Notes" section is found in the PR description, the action will post a helpful guide comment.
  The comment includes:

  • A short explanation + mention automated injection feature
  • A release notes template
  • A proposed draft generated from commit messages

  This serves as a non-intrusive way to guide contributors.
  If a guide comment from the action already exists, it won’t be posted again.

🔹 If both guide and inject_proposed_draft are enabled, the guide comment is skipped to avoid redundancy.

---

inject_proposed_draft

• Required: No
• Default: false
• Description:
  When enabled, the action will directly insert the generated release notes draft into the PR description.
  This provides a ready-to-edit section based on commit messages, saving the author time.

🔸 This takes precedence over the guide input. When both are enabled, the guide comment will not be posted.