Add npm version badge to README

Follow-up to #12857

[skip sauce] [skip validator]
Merge pull request #13766 from twbs/npm-badge

Add npm version badge to README
README: move badges to separate line

much badge, so wow
update shrinkwrap
bump grunt-contrib-connect to ~0.8.0
simpler and updated docs copy for icon font file paths
typo
relative
Merge pull request #13768 from twbs/font_files_docs

Simpler and updated docs copy for icon font file paths
fixes #13769
Merge branch 'master' of github.com:twbs/bootstrap
change how carousel indicators activate #12592
Merge pull request #13770 from twbs/fat-carousel

change how carousel indicators activate - fixes #12592
Update docs for Jekyll 2.x.
Fixes #13587: Switch to Kramdown for Markdown compiler in Jekyll
Merge branch 'master' of github.com:twbs/bootstrap
grunt
Integrate ZeroClipboard to easily copy code snippets
Refactor and restyle.
Remove unused variables and make tests pass.