fixup! fixup! fixup! Add writing-tests-guidelines.md (#612)

Author: lukasbriza

src/docs/contribute/writing-tests-guidelines.md

@@ -91,7 +91,7 @@ and before its comparison against the snapshot.
 - `props` - The properties passed to the component in the defined
 test scenario.
 
-## Formatting and code style
+## Formatting and Code Style
 
 ### Rules
 
@@ -108,7 +108,7 @@ visual impact on the appearance of the component.
 - For all possible combinations of multiple `propTests` should be used
 function `mixPropTests`.
 
-### Formate
+### Format
 
 - Prop test variants should be sorted alphabetically. If there are multiple
 prop tests like `feedbackColor`, `neutralColor`, etc., they should still be