Fix #10948: Clarify navbar example target in docs
Change all navbar example targets

According to comment on https://github.com/twbs/bootstrap/issues/10948#issuecomment-25751889 .
Merge pull request #10950 from twbs/docs-navbar-class

Fix #10948: Clarify navbar example target in docs
fix #10961
document .h1 thru .h6; fixes part of #10102
Merge pull request #10962 from twbs/doc-h1-thru-h6-classes

document .h1 thru .h6; fixes part of #10102
Merge branch 'master' of https://github.com/twbs/bootstrap