ci(style): Add EditorConfig and relevant GH Action

[mark-stopka]

Add EditorConfig and relevant GH Action to check compliance.

TODO:

• Fix existing non-compliance

[mark-stopka]

@scarmuega only .editorconfig needs to be checked, if it is up to your liking, upon merging and deploy of the gh-pages I will re-visit the mdBook Markdown files to see if I acciden tally broke anyting being unaware that Markdown uses two trailing_whitespace for newline; so I had trim_trailing_whitespace = true globally, that is now fixed for *.md files.

Lesson learned I guess =)

[scarmuega]

I've tested a local run of the mdbook and it seems to work ok.