[minor] Preserve whitespace and add branch as an input

[jazzsequence]

This pull request fixes two issues.

• The first commit addresses preserving whitespace in files, ensuring that, in markdown files, whitespaces represent line breaks correctly.
• The second commit adds a new input called "branch" which allows users to specify the branch to use as the base for pull requests and commit the changes back to. This allows plugins to use the correct base branch rather than the default branch.