Article on Type Signatures

[cartermp]

There should be an article on type signatures for F#. It should explain what they are, describe general patterns, provide examples explaining what each example mean, and show how they're used.

[eriawan]

@cartermp I think I will take this :)
Could you tell me where to put this article? Under which section this type signature documentation should be located?

[cartermp]

@eriawan Awesome! The article should go under the F# Language Reference section of the docs. We can figure out a good position within that section when you make a PR.

[eriawan]

@cartermp thanks! I'll create a WIP PR for F# type signature tomorrow 😄

[BillWagner]

@cartermp Does this article fix this issue?

[cartermp]

@BillWagner Not quite. This covers signature files, which do contain F# signatures. The article should probably be renamed to "Signature Files". I think there is still value in having a separate article or section about type signatures.