Replace ronn with pandoc

[tnir]

The urrent .ronn files in https://github.com/rubygems/rubygems/tree/master/bundler/lib/bundler/man are almost (common) Markdown while its extension is ronn, and so we might be able to use pandoc to do the same thing with less additional effort.

For example, ronn parses h1 markup incorrectly, so we need some workaround for it. ronn has not been maintained for 9 years.

cf.

• Use h1 instead of h2 for command name in command reference #823

[indirect]

Ronn is at least written in ruby, while pandoc is 1) huge and 2) pandoc filters add python as a build dependency, which will greatly increase future maintenance burden. I would strongly prefer fixing the bug in ronn rather than adding the entire python ecosystem into this repo.

[simi]

Btw. there is https://github.com/apjanke/ronn-ng, we can try migrate in there and help maintain that one if needed.

[tnir]

ronn-ng gem, mentioned by @deivid-rodriguez before, also looks unmaintained any more to me.

[simi]

@tnir we can help with maintenance. Is there anything particular to address for now?

[tnir]

As an alternative, you might want to check out pandoc which can also convert markdown into roff manual pages.

Ronn-NG also recommends using pandoc.

@simi take a look at #823

[simi]

As an alternative, you might want to check out pandoc which can also convert markdown into roff manual pages.

Ronn-NG also recommends using pandoc.

🤔 It doesn't, it just mentions it as an alternative, which is just copy paste from original ronn repository README.

[deivid-rodriguez]

Should we close this issue? I think everyone agrees to stick with a Ruby based library. Good old ronn has served us well for more than 10 years without a single upstream patch, this doesn't look like a domain that changes very often and needs a lot of maintenance.

[tnir]

I think we do not have to do this in this repo in favor of #996.