bb3: fix screenshot in notice
bb3: separate into two sections to make it consistent with bb3-usm
b9s-soundhax: add line to fix section ii header
region-changing: remove asterisks in section i, step 5
seedminer: fix numbered list
Updates guide to support 11.15. In particular:
- Removal of browserhax as main guide path -- not completely removed/stubbed yet.
- Removal of Seedminer out-of-date warning.
- Addition of Seedminer to get-started and site-nav recommended.