Add support for initial and following commit compares.

The problem with ordering is fixed.

* Fixed the wrong label used for chapter bug fixes. The bug is the correct value used in templates.
* Added FAQ section with received questions and prepared answers for them.

…ues (#21)

* Add new logic to detect PRs linking to Issue in Open state.
* Updated titles and defaults messages of warning chapters.

)

* Updated release notes mining logic to collect release notes from all comments.
* Update of README.md file to mention latest changes.

…ing from latest release created-at or published-at point. (#27)

Implemented new logic. User can newly decide if action will be searching from latest release created-at or published-at point.

* Prepared yml file. To test it has to be merged.

* Added two yml file to check and migrate PR release notes comment

* Implemented logic:
- Introduced a new warning chapter for closed not merged PRs.
- Introduced a new logic for filtering out Issues and PRs using user-defined or default labels.
- Introduced a new logic to control whether empty chapters are printed or not.

#34 - Introduce unit tests
- Implemented unit tests and mock logic.
- Rework of exit calls and exception throwing to use core.setFailed().
- Fix failing usage in yml file.
- Fixed bug in PR before 'since' decision logic.

- Improved logic to check release notes lines for presence of '-'. If not present add it with required indent.

…d chapters (#37)

#26 - Introduce the idea of PR without Issue as part of user-defined chapters
- introduced logic to work with PR without linked Issues like with Issues
- removed code duplication from logic extension "extraction of Release notes" from comments.
- fix similar methods to get issues and PR contributors.
- improved method `parseChaptersJson`
- Added new related test.
- Implemented logic to add PR without linking issues to custom chapters.
- Added new related test.
- Added logic to identify Duplicate mentions of already printed Issues or PR in custom chapters.
- Simplified duplicate string as GitHub does not support colors.

Fixed ordering of chapters. They are ordered from the oldest one (the lowest issue or pr number).