Standardizing on USE_STEAMWEBRTC because that seems like the more common
choice in the project.
Signed-off-by: Steven Noonan <steven@valvesoftware.com>
Delete roadmap section. The P2P item is basically done. P2P has its own
roadmap. We have the issues list, and all of those items are things we
want to do. I don't think having the roadmap is useful, or accurately
conveys priorities.
Go into just a bit more detail about the P2P basics in the main feature
summary.
Added some notes about symmetric connect mode, which is a really useful
and unique API feature.