Consistency of files under `./common`

[pchampin]

As pointed out by @davidlehn here:

I see the ci workflow here comments out the comparison with the wg common files such as https://github.com/w3c/json-ld-wg/blob/main/common/terms.html. Anyone know why? That check still exists in the api repo. The idea at one point had been to update those common docs then sync here.

I don't remember and git blame does not help much. (I didn't dig into the minutes at that time though).

Note that in the RDF & SPARQL working group, we had a similar mechanism, and moved to a different solution: the common files are now hosted in a separate repo, published on GH pages, and the respec files of the spec refer to the published versions of the common files.

[anatoly-scherbakov]

For reference, the commented out code is:

    #    git remote add -f b https://github.com/w3c/json-ld-wg.git
    #    git remote update
    #    git diff --exit-code remotes/b/main -- common

As another solution, w3c/json-ld-wg can be mounted as a Git submodule, and common directory under that submodule can be leveraged.

Dependabot is capable of proposing PRs which upgrade the submodule if a new commit is pushed to w3c/json-ld-wg.

[pchampin]

@anatoly-scherbakov yes, the submodule solution has also been experimented with in other WGs (or possibly this one, I don't remember), but was considered overly complex and confusing, especially for casual Git users.