Consider adding TSLint completed-docs rule

[jogold]

See https://palantir.github.io/tslint/rules/completed-docs/

I see a lot of PR comments/change requests about JSDoc...

[rix0rrr]

This is probably a low-effort fix. I feel the correct long-term solution solution is to put this into jsii, so that we can also require the correct doc comment annotations.

[eladb]

+1 about adding to Jsii

[rix0rrr]

Of course it's never so easy. Tried to enable the TSLint rule, the build choked on the very first package with a 100+ errors. jsii is going to be the only place where we can put this and not be annoying about it.

[eladb]

We can initially add it as a Jsii warning

[NGL321]

@rix0rrr does this still need attention?

[jogold]

Closed by #4645