update docker action server docs

[erohmensing]

Proposed changes:

• Improve documentation about building action server docker images and pushing them for use on servers
• close https://github.com/RasaHQ/rasa-x/issues/1947

TO DO: Create a redirect for https://rasa.com/docs/rasa/user-guide/running-rasa-with-docker/#adding-custom-actions

Status (please check what you already did):

• added some tests for the functionality
• updated the documentation
• updated the changelog (please check changelog for instructions)
• reformat files using black (please check Readme for instructions)

[TyDunn]

I read through both PRs. They both seem pretty good, but I will walk through the steps myself tomorrow

[akelad]

are we aware this headline is tinier than the actual font?

[erohmensing]

@akelad Yeah, it has to do with there being way too much information on this page. IMO that's another reason to take out the "building a bot in docker" info and move it away from the "deploying your assistant" page

Also something that we should make sure in the future doesn't happen in our sphinx theme (there should be a font size mininum for headers that is bigger than the regular text)

[akelad]

looking at this now, but gettign a bunch of warnings :D

/Users/akela/Documents/rasa-new/docs/user-guide/docker/building-in-docker.rst:121: WARNING: duplicate label model_training_docker, other instance in /Users/akela/Documents/rasa-new/docs/user-guide/how-to-deploy.rst
/Users/akela/Documents/rasa-new/docs/user-guide/docker/deploying-in-docker.rst:14: WARNING: duplicate label running-the-rasa-server, other instance in /Users/akela/Documents/rasa-new/docs/user-guide/how-to-deploy.rst
/Users/akela/Documents/rasa-new/docs/user-guide/docker/deploying-in-docker.rst:123: WARNING: duplicate label building-an-action-server-image, other instance in /Users/akela/Documents/rasa-new/docs/user-guide/how-to-deploy.rst

[erohmensing]

@akelad Haha sorry, it's in a middle state right now 😄TBH what would be best is a review of the updated docker action server before the content moved around, and then answering my 2 questions for you

the rest can still use a little restructing work, which is what i'm workin on 😋

[akelad]

i think generally the main landing page looks good and concise now. I'm not too sure about building with docker still either... But yeah i'll look at the custom action stuff specifically.

[akelad]

looks good generally but few things to change

[erohmensing]

Alright, let's try this again

[akelad]

few small things, few things i'm unsure about :D

[akelad]

good work! few more comments, you can decide which ones to address now and which ones to move to an issue for future fixing :D