Simplify / Fix Atom section in TEXTEDITORS.md
EDIT: Hmm. Either I was imagining things, or someone fixed this first bullet point when I wasn't looking and then hid the commit.
- "Atom settings" and "Atom packages" are at the same level (number of
#'s in Markdown) as "Atom". This is semantically incorrect.
EDIT: The real solution turned out to use a different approach, but still uses the link:
- The part of "Atom packages" above "Other useful Atom packages..." should be replaced with a link, incorporated into a sentence or two.