Docs: clean up links

No-Try: true
Docs-Preview: https://skia.org/user/api?cl=108502

Change-Id: I17547b53b50a00e4e9ad1704a032b5b0d14ea436
Reviewed-on: https://skia-review.googlesource.com/108502
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
3 files changed