Make sure code blocks are indented with four spaces
# What does this PR do?

In the documentation, many code blocks are indented with two or three spaces instead of 4. This PR enforces the use of 4 by:
- replacing indents of less than 4 by 4 in `make style`/`make fixup`
- checking there is no indent less than 4 in code blocks during `make quality`

Ah, I don't match the `.. code-block:: xxx`, thanks for pointing that out!<|||||>OK, the next problem is the one I was concerned about in the first place (which is why i didn't offer a perl one liner). Your fixing code isn't shifting the whole block, but only the outside lines. so it now results in broken python code - bad indentation. e.g. look at any code blocks in the diff that start with `class`, or `{`

So when you shift whitespace - you have to do it for the whole code block.<|||||>That's too hard to fix and will result in other problems (what about bash commands that have different indents with the \?). So I will remove the automatic fix and just put a hard error the user will have to manually fix.<|||||>> That's too hard to fix and will result in other problems (what about bash commands that have different indents with the ?). 

Bash has no indentation issues. Only python does AFAIK. Perhaps you meant multiline python fed into a bash shell?

I think it's about finding the difference in the required whitespace, and applying this exact change to the whole block should make it work. Since everything will be shifted by the same number of characters, which is what the manual fix would do anyway.

> So I will remove the automatic fix and just put a hard error the user will have to manually fix.

Sure, that would work just fine.

Thank you.<|||||>Ok, I have something that can do the whole block, but since this PR already badly treated some parts, I need to go back from a fresh master, so closing this one.