Review user documentation

[lyashevska]

Review and update Readme, in particular explain user profiles.

[lyashevska]

We need to proofread README.md more. Some suggestions are to change the first line which now reads:

"Spend less time setting up and configuring your new Python packages and comply with the Netherlands eScience Center Software Development Guide from the start."

Into something like:

"Spend less time setting up and configuring your new Python packages using this python template.

Also we need to add a section about user profiles and features that come with them.

[fdiblen]

done in #569