Compatible with Sprint 22 and above
Format HTML, CSS, and JavaScript files by Edit > Beautify menu or Cmd-Alt-L(Mac) / Ctrl-Alt-L(Win) key.
File > Install Extension
Paste https://github.com/drewhjava/brackets-beautify into Extension URL field
Download zip and extract into arbitrary directory (or clone source files), then move the folder to the extensions folder (you can open this folder by clicking "Help > Show Extensions Folder" menu).
JSBeautify: https://github.com/einars/js-beautify