Note that this post doesn't really cover how to stream media using WebRTC. First and foremost, because WebRTC mandates the use of DTLS to encrypt the RTP flow, thus a plain RTP stream won't work. A more apt title would be "How to use FFmpeg to generate an encoded stream that happens to match the requirements for WebRTC".
Still, thanks for the article; it is always interesting to see specific applications of the FFmpeg command line, because in my opinion after having read them top to bottom, FFmpeg docs are very lacking in the department of explaining the whys.
Random example: You read the docs of genpts and it is something on the line of "Enables generation of PTS timestamps". Well, thank you (/s) But really, when should I use it? What does it actually change between using it or not? What scenarios would benefit from using it? Etc. Etc.