Push docker image to html2rss/web

[gildesmarais]

Note

An image is available to pull at https://hub.docker.com/r/gilcreator/html2rss-web.

• There's a new html2rss organization on docker hub.
• push docker image to html2rss/web
• update readme
• have a nice presentation on docker hub
• migration plan from gilcreator/html2rss-web (manual? automatic? dockerhub options to consider?)