Give a brief explanation of the features of interest and how feature
detection works on the platforms currently supported.
Change-Id: If4d4107aca3c1bc403e9ae27e42c1c77f6cc80b1
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/5554431
Reviewed-by: Justin Green <greenjustin@google.com>
Reviewed-by: Frank Barchard <fbarchard@chromium.org>
