Added more details
Added more details

* added further detail to intraframe direction prediction 
* Added some more resources, most notably wiki.multimedia.cx and the HEVC book
* The company was not called TrueMotion, TrueMotion was the name of the first codec the Duck Corporation produced
* Further clarification on the differences between h264/h265.
leandromoreira/digital_video_introduction,leandromoreira/introduction_video_technology