WebView: misc docs changes for WebSettings

No change to logic, only docs changes.

This is mostly just formatting changes to documentation. Changes fall
into a few categories:

 * Linkify ({@link}) or codify ({@code})
 * Spelling errors

Test: make docs (looks better)
Change-Id: Ibcd762ab06e51451a53bbce5860cc137bee22ccf
1 file changed