MarkdownLint - Improve output by fixing MD022 and MD040

[DEberhardt]

Markdownlint in VSCode complains about MD022 and MD040 mostly (MD031 as well, but that goes away with fixing MD022)
As far as I can see, these might be fairly easy to implement

MD022 - Headings should be surrounded by blank lines
MD040 - Fenced code blocks should have a language specified

Environment data

v0.14.0

[DEberhardt]

#496 addresses MD022

for MD040 I see that the schema already has a text block for the language in the Syntax, but it is empty when built.

[DEberhardt]

Updated commit now also addresses MD040
Ready

[DEberhardt]

hm. That doesn't seem to work for me :/