Add in MARKs to .macos for minimap sections

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Hello 👋

Thanks a lot for all the great options here and the links to other resources :) A thing I just changed that's making navigating the .macos file a bit easier is changing all of the section headers to start with `# MARK:` so that they show up in the minimap. I've found it helpful for a file this large. We'd need to remove the last `#` at the end of these header lines so that the text for the minimap is just the characters to prevent an unneeded `...` from the MARK headers thinking the title includes all the trailing whitespace.

Happy to send this change along, or maybe others would find using this change in their versions helpful 😊

Thanks again!

Start in the .macos file and inspect its section header lines. Update each header to use the # MARK: form and remove the trailing # so the minimap title does not include unnecessary trailing whitespace; done means all section headers follow this format.

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