[Feature Request] enforce gitignore

[Brilator]

Some recent user issues were obviously due to ARCitect / git failing to add windows / office temporary binary files (starting with "~$").

• cloned a user ARC containing such files
• removed the .git
• git-reinitiated via ARCitect
• tried to commit, ran into error: pathspec pointing to a missing excel temporary
• Now the overall ARC was really messed - with other files missing.