Update KiCad.gitignore

[krishnans2006]

Reasons for making this change: When using KiCad with git/GitHub, I always use a modified version of the official KiCad.gitignore file with these changes applied. New KiCad versions have changed the way backups and autosaves are performed, and this PR hopes to reflect those changes in this repository.

Enumerated list of changes:

1. Add *-cache*
2. Generalize *.sch-bak to *-bak and *-bak*
3. Add ~*
4. Add #auto_saved_files#

Links to documentation supporting these rule changes:

• 1, 2, 4: TechOverflow notes the KiCad-generated gitignore. Changes 1, 2, and 4 make this repo's file more consistent with the KiCad recommendation.
• 3: Reddit notes the introduction of lock files in KiCad v8.

Another Credit: https://github.com/github/gitignore/pull/4176#issuecomment-1379664803 for one of this PR's changes.

[github-actions[bot]]

This PR is stale because there have been no updates in 90 days. It will close after 180 days of inactivity. Leave a comment if you want to keep it open :smile:

[krishnans2006]

Still looking to get this merged (just rebased on main). Happy to make any requested changes.

[wirecat]

@krishnans2006 I see a merge conflict again. Could you please resolve it?

[krishnans2006]

@krishnans2006 I see a merge conflict again. Could you please resolve it?

@wirecat done!