Allow for PRs to validate changes without updating docs

[SeanTAllen]

Currently, there's no way to have a CI tasks that generates missing docs without checking in the results. This makes it hard to test that changes work correctly.

I see this as a 2 step thing to tackle:

Step 1:

• Break building-missing-docs.sh up so it is composing a number of functions.
• Have building-missing-docs.sh only build
• Create a step that can check-in each of the newly created docs

Step 2:

• Create a script that allows you to test the creation of all docs whether they exist or not. This, while taking longer, would catch many more possible bugs when doing CI as often on CI, there might be no missing docs to build

[SeanTAllen]

Currently, opening a PR for a new manifest, it will result in the docs from that PR being built. So the PR gets opened. It gets run, additional commits for the docs are added. Example:

If CI auto-cancellations are on, this results in weird things like the build of some docs being deleted.

It's an interesting idea to have docs built during the PR, then we can see what the final documentation would look like and the end user could spot troubles.

Because this is what we have right now, I'm turning off CircleCI auto-cancellations for this repo.

[SeanTAllen]

This is no longer applicable given the recent architecture changes.

See https://gist.github.com/SeanTAllen/1ecefb51c606c1a5b5b278b89aa49f4e for more information.