At the moment, only "syntax=asciidoc" was specified. The
asciidoc_filetype.vim that is distributed with Asciidoc gives the
installer two options -- to either associate every *.txt file with
asciidoc or to try to decipher whether or not the file is an asciidoc
using the first 50 lines.
So it's not given that a developer will open the *.txt files with
ft=asciidoc, and so it's helpful to have it explicitly in the modeline.
This reverts commit 1455b9d27224b1289e7762fef3c4d158c7074877.
"Command line" should only be hyphenated when it is a /leading/ compound
/modifier/. For example, "command-line interface." See CMOS (or
Strunk/White) for more information.
