Tracking mechanism for improvements

[nik9000]

Right now problems either cause the docs build to fail or are totally ignored. It'd be nice to have a class of problems that can be "let through" intentionally. Say, like, for broken links. If we had this for broken links we could click a button in the build that allows the build to succeed even if there are broken links. Then subsequent builds would pass so long as they have the same broken links or fewer of them.

We could use this mechanism to ratchet down all kind of low priority things like examples that are so wide they require scrolling or deprecated syntax.

[nik9000]

I think we'd need this if we were doing spell checking too.