Added 4:2:2 color subsampling schema
Added 4:2:2 color subsampling schema

4:2:2 is one of the most commonly used subsampling schemas (among 4:4:4 and 4:2:0) and should be part of the listing here.
Also perhaps sorting the 4:4:4, 4:2:2 and 4:2:0 to the beginning of the listing would be a neat idea.
leandromoreira/introduction_video_technology,leandromoreira/digital_video_introduction