Add support for pointer fields.

[scottwis]

[haines]

I think the check here needs to be updated to account for the possibility of *bool fields (otherwise you can't make a *bool field negatable): https://github.com/alecthomas/kong/blob/556f8b773b24e22c5dcb05a1a740567c19d1ef99/tag.go#L174

Also here: https://github.com/alecthomas/kong/blob/deebf0b09b7bdda61ec299ab90aaaa341436dd4b/model.go#L311

[scottwis]

@haines I think bool pointers should work just fine. I added some tests for various bool* cases. Let me know if there's something I missed.

[haines]

@scottwis could you please check if you can use the negatable:"" tag with *bool fields (might be worth adding a test case for it)?

[scottwis]

@alecthomas @haines @shueybubbles

I believe I have all comments addressed. Can you please take another look?

[alecthomas]

Ping. This is not passing lint.

[jh125486]

@scottwis should I fix this (either //nolint or remove the fields) and push it?

[stevekm]

I needed this exact feature, hope it can get merged in soon. Thanks for implementing this :)

[alecthomas]

This was merged in #296

[alecthomas]

Thanks for all the work and apologies for the delay in responding.

[stevekm]

this is perfect thanks so much