new feature: move issue (with comments) to another project

Hi there,

Thanks for this great app. It's exactly what I was looking for to manage small personal projects!

An example of how I use this feature (changing projects).

- "Project A": contains a list of issues or to-dos that I would like to finish in the project.
- "Project A v1.1.0": contains a list of issues or to-dos that I have fixed, or am working on for this version of the project.

I use the feature in the pull request to move an issue from the "Project A" that I would like to work on so that I can release it in "v1.1.0".

Cheers