Correct grammar

Jekyll is the third person singular (it), so it should be 'its documentation', not 'their documentation'.
Merge pull request #10932 from ZDroid/patch-1

Correct grammar
Fix #10948: Clarify navbar example target in docs
merge in new ads
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
fixes #10961: change variable names in grid docs
Merge branch 'master' of github.com:twbs/bootstrap
fix #10961
update gitignore to restore the ruby-version ignore and rename section to all docs stuff
Merge branch 'master' of github.com:twbs/bootstrap

Conflicts:
	css.html
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
run grunt
Fixes #10959: round the .lead values down to nearest pixel via floor()
Merge branch 'master' of github.com:twbs/bootstrap
Half fix for #9855: Don't fuck with margins for open modal dialog on account of Lion non-scrollbars and inconsistencies elsewhere
Fixes #10126: Update responsive test cases to properly highlight hidden class examples