Merge branch 'mm/doc-tt' into maint

More mark-up updates to typeset strings that are expected to literally typed by the end user in fixed-width font. * mm/doc-tt: doc: typeset HEAD and variants as literal CodingGuidelines: formatting HEAD in documentation doc: typeset long options with argument as literal doc: typeset '--' as literal doc: typeset long command-line options as literal doc: typeset short command-line options as literal Documentation/git-mv.txt: fix whitespace indentation