Info/Documentation for static functions in p5.Vector

[keho98]

#346

Adds angleBetween to documentation
Adds examples for most instance methods which have a static version
Refines description of add, sub, mult, and div to more accurately describe p5.Vector
Fixes minor syntax issue with main example

The one part of p5.Vector I didn't really touch on was method chaining. As this functionality for the Vector class is new to p5 and not in processing, it feels like there needs to be a bit more discussion on how to properly present & introduce chaining across the libraries in p5.

[lmccart]

thanks @keho98! @shiffman do you have time to give this a quick look over review? if it's easier, you could pull in @keho98's branch, run grunt yui and see the pages displayed from the /docs/reference/ folder. if you're busy let me know, and I'm happy to review it.

@keho98 I think good call on holding off on chaining for now. it is something that we've been sort of informally adding in. it makes sense to me because the pattern feels very javascript-y, but I think we will need to do a solid pass over the library and add it in anywhere it's missing before documenting it as working functionality.

[shiffman]

Yes, I'll take a look soon. Thanks for this great work @keho98!

[lmccart]

@shiffman I looked over this and it seems all correct as far as I can tell, is it ok if I go ahead and merge it in?

[shiffman]

Gosh, so so sorry I never followed up about this. I just looked it over and agree it looks good. I have a few minor nits that I might adjust (a couple missing semi-colons and I might prefer using variables v1, v2 and v3 rather than v, v1, v2. But these are minor. After you merge I can take a pass and make some tweaks.

I'll open an issue for myself.

[shiffman]

And thank you again @keho98!