[e] (0) Add a note to clarify window.document, and fix some spellings
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=25730
Affected topics: CSS, Canvas, DOM APIs, HTML, HTML Syntax and Parsing, Security, Video and Audio, Workers

git-svn-id: https://svn.whatwg.org/webapps@8801 340c8d12-0b0e-0410-8428-c7bf67bfef74