- Additional.lyx: update description of multiple columns
- multicol.lyx: remove this file because its content is now completely in Additional.lyx
(We once described multiple columns in 3 different files, Additional.lyx, Customization.lyx and multicol.lyx. We now have only one place.)
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@39355 a592a061-630c-0410-9148-cb99ea01b6c8
