chore(CHANGELOG): introduce perf() section for performance-related commits

[matsko]

Instead of using fix() or chore() when labelling a commit which improves
speed or performance use perf(). Perf commits will be listed in the
CHANGELOG under "Performance Improvements".

For example:
perf($animate): cache all getComputedStyle operations to reduce additional reflows

[mary-poppins]

Hi Matias!

[IgorMinar]

lgtm.

please also update the commit message conventions doc linked from Contributing doc

[matsko]

@IgorMinar done.

[petebacondarwin]

And the https://github.com/angular/angular.js/blob/master/validate-commit-msg.js and its spec.

[petebacondarwin]

BTW, I always assumed that such performance related commits went under "refact"?

[IgorMinar]

I'm sorry, but I wasn't able to verify your CLA signature. CLA signature is required for any code contributions to AngularJS.

Please sign our CLA and ensure that the CLA signature email address and the email address in this PR's commits match.

If you signed the CLA as a corporation, please let me know the company's name.

Thanks a bunch!

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[mgol]

This would be great. I submitted a PR labeled feat as it introduces a new jqLite method but the only reason for that is a huge perf gain: #4457

I can imagine that this PR didn't get much attention because of this feat label that made it look not so serious where in fact this improves performance a lot.

Having such things labeled as perf might help them to get more attention.

[Narretz]

Can't this be included in refactor?

[matsko]

We thought about that, but I believe refactor, chore and all other uncommon subjects are stripped in the CHANGELOG. The point is to include a separate section for performance-related improvement since so much work may go into them, but the community ends up having no idea that they were in a release.

[matsko]

@IgorMinar @petebacondarwin done (both of them).

[matsko]

MERGED

[matsko]

Landed as a14266e

[Narretz]

just stumbled upon this google doc: https://docs.google.com/document/d/1QrDFcIiPjSLDn3EL15IJygNPiHORgU1_OOAqWjiDU5Y/edit?pli=1 (Git Commit Message Conventions
) If this is still relevant, 'perf' should be added to it.