Remove examples/internal

[Sean-Der]

Users find it frustrating that example code doesn't work out of tree. This makes copying the examples out of the repo easier.

Relates to pion/webrtc#1981

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 266 lines in your changes missing coverage. Please review.

Project coverage is 0.00%. Comparing base (96595fe) to head (b5b268a).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
gstreamer-send-offer/main.go	0.00%	26 Missing ⚠️
c-data-channels/main.go	0.00%	24 Missing ⚠️
ffmpeg-send/main.go	0.00%	24 Missing ⚠️
gstreamer-receive/main.go	0.00%	24 Missing ⚠️
gstreamer-send/main.go	0.00%	24 Missing ⚠️
play-from-disk-h264/main.go	0.00%	24 Missing ⚠️
play-from-disk-mkv/main.go	0.00%	24 Missing ⚠️
rtmp-to-webrtc/main.go	0.00%	24 Missing ⚠️
save-to-webm/main.go	0.00%	24 Missing ⚠️
sip-to-webrtc/main.go	0.00%	24 Missing ⚠️
... and 1 more

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #241    +/-   ##
=======================================
  Coverage    0.00%   0.00%            
=======================================
  Files          27      25     -2     
  Lines        2072    2246   +174     
=======================================
- Misses       2072    2246   +174     

Flag	Coverage Δ
go	0.00% <0.00%> (ø)
wasm	0.00% <0.00%> (ø)

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