[TYPO3-doc] Small improvements to official documentation template, headings

[Daniel Bruessler]

Hello,

>> I like the large left indent.  However I would suggest to let the
>> headings start at the very left so they visually stand out of the text.
> 
> Yes I thought about that. I quite like it. I'll give it a try.

I like the boxes, too - but this is now much cleaner and the images are
seeable very good. The gray background has "hidden" the images.

Cheers!
Daniel