Linter needs to check pattern and link

[nimbinatus]

The linter needs to be updated to enforce single words in the pattern subfield of the document field and also to ensure the link to the document is to an actual github.com link.

cc @juliadenham @jjasghar

/assign me (I know there's no slash command, but I'll take care of this :) )

[nimbinatus]

After evaluating this more, I suspect these really should be warnings instead of errors (notices instead of enforcement) as this is more to alert the triager considering this does not affect the actual code or model runs (i.e., it's grounds for requesting edits due to current legal requirements rather than long-term design decisions)