Use squash and merge for merging PR

[MicBun]

Recently we merged commits with Create a merge commit This will make our commit history messy if there are a pull request with multiple commits. I suggest we use squash and merge to keep things neat. Another option here is to disable the merge commit and simply use squash instead to prevent accidental merge with multiple small commits.

[zolotokrylin]

Good point. I have changed the setting. Now only the Squash option should be available. Please check when there's a chance. Thanks