Removing dead links on the "Getting Started" page.
Removing dead links on the "Getting Started" page.

The "getting started" and "WebRTC internals" pages seem to have been
removed since they contained outdated information.

webrtc/webrtc-org,Scintillo/webrtc-org,Scintillo/webrtc-org,Scintillo/webrtc-org,samdutton/webrtc-org,louquillio/webrtc-org,samdutton/webrtc-org,webrtc/webrtc-org,louquillio/webrtc-org,louquillio/webrtc-org,webrtc/webrtc-org