Add tip on renaming files tracked with git

[egrace479]

Also removes the reference to emacs.

[egrace479]

I'd suggest this smaller change to avoid the git add . seeming like a suggested method. Then I can add another "Pro Tip" at line 46 to the effect:

After using git add <folder> or git add <regex> (a pattern match), run git status to ensure that all intended files--and only intended files--are staged for commit.

[thompsonmj]

I'd suggest this smaller change ...

That's good, though I often just list the files by name, e.g. git add <path/to/file1> <path/to/file2> <path/to/file3> to scope the commit well. But for brevity, it looks good as is.

[thompsonmj]

Looks good!