Ticket #3734: improve syntax documentation for mcedit

[jip]

Document text sequences interpreted by mcedit.

Proposed changes

Put a table with patterns correspondence 'mcedit vs. pcre2' from #3734 into doc/man/mcedit.1.in file.

• Resolves: Improve the syntax documentation #3734

Checklist

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• I have referenced the issue(s) resolved by this PR (if any)
• I have signed-off my contribution with git commit --amend -s
• Lint and unit tests pass locally with my changes (make indent && make check)
• I have added tests that prove my fix is effective or that my feature works
• I have added the necessary documentation (if appropriate)

[zyv]

@jip, thanks for working on this!

Unfortunately, you used the wrong roff syntax, so the man pages cannot be rendered correctly. Could you please fix the following roff warnings:

• mcedit.1.in: unescaped dash ('-')
• mcedit.1.in:483: warning: macro '@\.@' not defined
• mcedit.1.in:497: warning: tbl preprocessor failed, or it or soelim was not run; table(s) likely not rendered (TE macro called with TW register undefined)
• mcedit.1.in: forbidden pattern '\\'
• mcedit.1.in: forbidden pattern '\.'

Also, please sign off your commit as instructed in the PR template.

Thank you!

[jip]

Done.

[zyv]

/rebase