Allow omitting '/**/*' in include

[DanielRosenwasser]

This is a huge time sink for users who are going to think

"include": ["./foo/bar"]

is equivalent to

"include": ["./foo/bar/**/*"]

At the very least, we can give a warning.

Of note, "exclude": "./foo" seems to be equivalent to "exclude": "./foo/**/*, so why is there an inconsistency here?

[mhegazy]

@riknoll can you take a look.

[cdaringe]

the docs, as mentioned in #11425, already declare that this is how it works. FYI!

[basarat]

I have a section for it in TypeScript deep dive as well : https://basarat.gitbooks.io/typescript/content/docs/project/files.html 🌹

[mhegazy]

ppl keep running into this issue. we need to fix this sooner.