chore(release): git add CONTRIBUTING too

CONTRIBUTING.md

@@ -12,8 +12,11 @@ Hi (future) collaborator!
 
 - [Where to start?](#where-to-start)
 - [Development workflow](#development-workflow)
+  - [Local example](#local-example)
+  - [Documentation website](#documentation-website)
 - [Adding/Updating a package](#addingupdating-a-package)
 - [Removing a package](#removing-a-package)
+- [In case of shrinkwrap madness](#in-case-of-shrinkwrap-madness)
 - [Commit message guidelines](#commit-message-guidelines)
   - [Revert](#revert)
   - [Type](#type)
@@ -23,7 +26,6 @@ Hi (future) collaborator!
   - [Footer](#footer)
 - [Stash your commits](#stash-your-commits)
 - [When are issues closed?](#when-are-issues-closed)
-- [Milestones](#milestones)
 - [Releasing](#releasing)
   - [Beta releases](#beta-releases)
 - [Hotfixes](#hotfixes)

scripts/release

@@ -68,7 +68,7 @@ npm run doctoc
 
 # git add and tag
 commitMessage="v$newVersion\n\n$changelog"
-git add src/lib/version.js npm-shrinkwrap.json package.json CHANGELOG.md README.md
+git add src/lib/version.js npm-shrinkwrap.json package.json CHANGELOG.md README.md CONTRIBUTING.md
 printf "$commitMessage" | git commit --file -
 git tag "v$newVersion"