Set error messages to link to relevant docs

[pop]

Error messages should link to appropriate documentation in addition to an error message.

@osuosl/devs @jordane @Kennric thoughts?

[jordane]

to summarize the IRC conversation:

• giving a direct url means we commit to maintaing those docs for a very long time
• giving a direct url mayhave issues if someone else modifies code but doesn't change the documentation links
• giving some other reference to the docs (error code, chapter & section) could be useful, but also has disadvantages
• this is ultimately a really good idea, but we should be careful about how we do it.

[iankronquist]

Why not make a /docs endpoint which hosts the docs which are already in the repo, and then you can provide links to that? If they live on the same server they shouldn't be out of date or unreachable.

• The docs should be maintained as long as the app is around.
• You can get the url dynamically like "http://#{fqdn}/docs/error_4.html" or something.
• I think we have this already?

[iankronquist]

https://github.com/osuosl/timesync-node/compare/docs-spike
Obviously you have to build the docs.