Note how to access Perf in docs
[Docs] Add recent addons to addons.html; tweak wording

Add PureRenderMixin and Perf to this page. Also, I think it's better if the link titles reflect the name used by these addons.
Merge pull request #1893 from chenglou/docs-bar

[Docs] Add recent addons to addons.html; tweak wording
Merge pull request #1882 from glenjamin/patch-1

Note how to access Perf in docs