[AIRFLOW-5323] Fix teething proglems breeze

[potiuk]

Make sure you have checked all steps below.

Jira

• My PR addresses the following Airflow Jira issues and references them in the PR title. For example, "[AIRFLOW-XXX] My Airflow PR"
  Those are for issues solved in 5 separate commits (all found during first Breeze workshop)

  • https://issues.apache.org/jira/browse/AIRFLOW-5323
  • https://issues.apache.org/jira/browse/AIRFLOW-5324
  • https://issues.apache.org/jira/browse/AIRFLOW-5325
  • https://issues.apache.org/jira/browse/AIRFLOW-5326
  • https://issues.apache.org/jira/browse/AIRFLOW-5327
  • https://issues.apache.org/jira/browse/AIRFLOW-5329
  • better documentation about resources usage for Breeze

Description

• Here are some details about my PR, including screenshots of any UI changes:

Issues discovered during first Breeze workshop (AKA Teething problems).

Tests

• My PR adds the following unit tests OR does not need testing for this extremely good reason:

Commits

• My commits all reference Jira issues in their subject lines, and I have squashed multiple commits if they address the same issue. In addition, my commits follow the guidelines from "How to write a good git commit message":
  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Documentation

• In case of new functionality, my PR adds documentation that describes how to use it.
  • All the public functions and the classes in the PR contain docstrings that explain what it does
  • If you implement backwards incompatible changes, please leave a note in the Updating.md so we can assign it to a appropriate release

Code Quality

• Passes flake8

[potiuk]

Small but annoying issues I was able to discover when I tried it with the attendees of NYC Apache Airflow Meetup. I split it to separate issues but submit it as one PR to make it easier/faster to merge.

[kaxil]

Suggested change

	configured to be able to run ``docker`` commands directly and not only via root user. You user
	configured to be able to run ``docker`` commands directly and not only via root user. Your user