[typo] Inconsistent case in headings

[j9t]

(Lazy report, I had wished the group to accept reports also through the public-annotation@ list.)

https://www.w3.org/TR/2017/NOTE-annotation-html-20170223/:

1. The case used in headings is inconsistent. The document seems to prefer title case but occasionally uses sentence case or something in between. Compare “Annotations Embedded as JSON-LD” then “Annotating a Web page image”; but even if lower-level headings are supposed to switch from headings to sentence case, some listings as under “Motivation” may still require attention—here, compare “Personal Annotating” but “Lighweight, decentralized Annotation Tools”.

Also:

• Note the typo, “Lighweight”.

[azaroth42]

Summary: Headings should consistently use Title Case. Typo of "Lighweight" for "Lightweight".