Spelling and capitalization fixes from GitHub PRs

Inspired by
* https://github.com/google/skia/pull/18
* https://github.com/google/skia/pull/22

Change-Id: I4c092978f928ff2f589b6440d1fcdd846fa2b56f
Docs-Preview: https://skia.org/?cl=342925
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/342925
Reviewed-by: Heather Miller <hcm@google.com>
Commit-Queue: Ravi Mistry <rmistry@google.com>
10 files changed