css coding guidelines initial commit

to be discussed in pull request process
dont mix whitespace and tabs
copied fromat block from ideomatic css
add exeptions from ideomatic css
rules for sass/scss/preprocessors
changes the title as it is too complex
Remove duplicate line
remove overspecific language

we see a selector always as an 'discrete' selector…
add ruleset as a alternative word for css rule
Merge branch 'css_sass_guidelines' of github.com:codecandies/coding-guidelines into css_sass_guidelines
changed from no nesting to max 3 levels
add nesting to declaration order
Refine variable names for colors
Specify github MD syntax highlighting language
Merge pull request #1 from codecandies/css_sass_guidelines

Proudly merged. ;)