Update Community-Plugins.rst

Link to sbt-lock
Merge pull request #1207 from tkawachi/patch-2

Update Community-Plugins.rst
Documentation page title width overlaps search box making it unselectable
Merge pull request #1222 from flurdy/doc-titlewidth-0.13.1

Documentation page title width overlaps search box (0.13.1)
add reference to sbt-git-stamp plugin
Merge pull request #1231 from pkaeding/pk/sbt-git-stamp

add reference to sbt-git-stamp plugin