outdated blog post in register_meta doc for 4.6 update

[Mista-Flo]

Hello,

The 4.6 WordPress version update the register_meta function, in the PHP Doc header of the function, there is a link to the Core blog post that explains changes, but it's an outdated post, since the direction of the function change's has evolved.

Now it should be ​https://make.wordpress.org/core/2016/07/20/additional-register_meta-changes-in-4-6/ instead of ​https://make.wordpress.org/core/2016/07/08/enhancing-register_meta-in-4-6/

[Mista-Flo]

Fix phpdoc

[ocean90]

IIRC this was intentionally because the second post doesn't include all the information which the initial post has.

[morganestes]

My patch 38254.diff​ has the same changes as the one from @Mista-Flo, just from outside src. His patch wasn't applying with grunt patch so I tried with the same info and uploaded it from grunt to test it out.

[morganestes]

@ocean90 The note at the top of the original post directs readers to use the second one. Maybe it would be better to include the notes from those posts in the inline docs with the correct usage instead of just linking to one or the other?

[ocean90]

I don't think we should change the posts. Maybe there should be a page on devhub instead. I'm leaving the decision to @DrewAPicture.

[DrewAPicture]

I think the best move here would be to link to the ticket (#35658) as the canonical history for the changes introduced in 4.6. All of the discussions, decision making, and conclusions are included there.

[Mista-Flo]

Refresh : Add core ticket @link to register_meta php doc

[Mista-Flo]

I have made a new patch according to your comment.

[jorbin]

In 39066:

Update link in register_meta about 4.6 changes

The blog post, while originally canonical, was later updated to include additional changes. The ticket includes all the changes and alot of rational for why things changed.

Props Mista-Flo, DrewAPicture, morganestes.
Fixes #38254.