Add optional feature to modify checklist inside PR description instead of using comments

[ssbarnea]

Checklists in comments can easily be missed and having a dynamic checklist inside the PR title would be extremely useful and popular. Obviously this needs extra permissions for the action and a little bit of logic for inserting or updating the PR checklist. Still, the benefit would be huge.

Please consider this feature request. If you find the time to do it, I will probably become the no1 promoter for this action. I wrote and maintain few reusable actions myself but I am aware that I cannot have another "kiddo" to take care of. In fact I even created a github organization specially for hosting and maintaining github actions, with the goal of having multiple maintainers that can step in and help with various actions, thus reducing the change they would endup as abandonware.