Fix path to preferences.txt on Windows

[terrillmoore]

The documentation was wrong for Windows, for locating the preferences file. This update matches modern Windows (7..10), but is probably not right for XP.

[terrillmoore]

Sorry, I see that I missed a trailing '*' in the markdown, which messes up formatting. I'll resubmit.

[PaulStoffregen]

Actually, on Macintosh the path is ~/Library/Arduino15/preferences.txt

[PaulStoffregen]

And on Windows, the unix "~" syntax doesn't really apply. The correct syntax is: %LocalAppData%/Arduino15/preferences.txt

[terrillmoore]

Well... actually, if you're using git bash on WIndows, which practically everybody does these days, ~/AppData .... is the easiest way to get to the file.

If not using Git Bash, then we should replace / by \ for all Windows paths, because / is sometimes rejected by overzealous parsers.

[matthijskooijman]

@terrillmoore, for future reference, you could have force-pushed to your original branch and have this PR updated instead of creating a new one.

[PaulStoffregen]

using git bash on WIndows, which practically everybody does these days

[citation needed]

[terrillmoore]

@terrillmoore, for future reference, you could have force-pushed to your original branch and have this PR updated instead of creating a new one.

Thanks, @matthijskooijman I'll bear that in mind.