Add fb-fix-fsselection.py documentation to README.md
Add fb-fix-fsselection.py documentation to README.md

(issue #1139)

moyogo/fontbakery,googlefonts/fontbakery,graphicore/fontbakery,googlefonts/fontbakery,googlefonts/fontbakery,moyogo/fontbakery,graphicore/fontbakery,graphicore/fontbakery,moyogo/fontbakery