Fixes issue #272. Updates grammer in Extend section.
Fixes issue #274. Corrects usage of pseudo-class.
Merge pull request #273 from carwin/issue-272-extend-feature-grammar

Fixes issue #272. Updates grammer in Extend section.
Merge pull request #275 from carwin/issue-274-pseudo-class-usage

Fixes issue #274. Corrects usage of pseudo-class.
Update plugins.md
Merge pull request #276 from bassjobsen/patch-15

Update plugins.md
Merge pull request #1 from less/master

merge base