Fixed the code example in ## Config File
`lang: de` throws a `Validation Warning: .appConfig should NOT have additional property: lang` while `language: de` works as expected.
This changes all of the documentation markdown files to follow
the same rules. The rules I've applied are from
https://github.com/DavidAnson/markdownlint/blob/v0.25.1/doc/Rules.md
The reason I felt it was necessary
to change all the files was
that there were a lot inconsistencies in how the markdown was used.
Ranging from header levels to some headers having a new line before
content and some not.
Removed trailing whitespaces and extra newlines. Added some missing
punctuation. Replaced unicode characters that aren't commonly used
with the more common character.
The replaced unicode characters are
- ’ (U+2019) to ' (U+0027)
- “ (U+201C) to " (U+0022)
- ” (U+201D) to " (U+0022)
