DockerHub page not up to date with this repo

[arielpontes]

I was trying to understand the versioning system described in this page while still making sense of the fact that the version I use (2.9) uses Python 3 in spite of not having "-py3" in the name. After much investigation it turns out the DockerHub page is simply out of date, as I could read in this repo that "since Scrapy 2.0 all branches are Python 3 only". If somebody with the proper permissions could update that page, I think it would be helpful to prevent others from going through the same trouble as me.