Rename files in doc/man/arcyon, generate with loop

Simplify the routine to generate the arcyon doc text files to use a
loop.

Rename the arcyon doc text files so that they use a dash to separate the
words in multi-word subcommands. e.g. 'raw-diff' instead of 'raw_diff'.
This is more consistent and is easier to reduce to a loop.

Test Plan:
Ensure git reports that the files are renamed and have no content
changes.  'git rm' the doc files first to make sure they are all
re-generated.
gen_doc: add arcyd commands to generated man texts

Make it easier to access the arcyd per-command documentation by
maintaining a copy in the repo, this also means it's published anywhere
the source code is visible.

It's important that the documentation is usable, by re-generating in
the pre-commit scripts we ensure that the output version is reviewed
alongside the code that changes it.

Test Plan:
Review the doc after running
./gen_doc.sh
gen_doc: add barc commands to generated man texts

Make it easier to access the barc per-command documentation by
maintaining a copy in the repo, this also means it's published anywhere
the source code is visible.

It's important that the documentation is usable, by re-generating in
the pre-commit scripts we ensure that the output version is reviewed
alongside the code that changes it.

Test Plan:
Review the doc after running
./gen_doc.sh