gitcli.txt: typeset pathnames as monospace

gitcli.txt: typeset pathnames as monospace

Commit 1bc1e94091 (doc: option value may be separate for valid reasons,
2024-11-25) added a paragraph discussing tilde-expansion of, e.g.,
~/directory/file.

The tilde character has a special meaning to asciidoc tools. In this
particular case, AsciiDoc matches up the two tildes in "e.g.
~/directory/file or ~u/d/f" and sets the text between them using
subscript. In the manpage, where subscripting is not possible, this
renders as "e.g.  /directory/file oru/d/f".

These paths are literal values, which our coding guidelines want typeset
as verbatim using backticks. Do that. One effect of this is indeed that
the asciidoc tools stop interpreting tilde and other special characters.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>