Collect Style class comment

[Ducasse]

We managed to find time to document classes related to BlStyles and BlElementStyle. Below are the links to the corresponding documentation:

• BlStyles: https://github.com/feenkcom/Bloc/blob/master/src/Bloc/BlStyles.class.st
• BlElementStyles: https://github.com/feenkcom/Bloc/blob/master/src/Bloc/BlElementStyles.class.st
• BlForwardedElementStyles: https://github.com/feenkcom/Bloc/blob/master/src/Bloc/BlForwardedElementStyles.class.st
• BlForwardedStyles: https://github.com/feenkcom/Bloc/blob/master/src/Bloc/BlForwardedStyles.class.st
• BlElementStyle: https://github.com/feenkcom/Bloc/blob/master/src/Bloc/BlElementStyle.class.st Please take a look and let us know if you have further questions related to styles. We will let you know when there are answers to other questions.

P.S. While working on the docs it became apparent that there is an unfortunate typo in the method name BlElement>>#style which should be BlElement>>#styles (plural) since it returns an object that represents a collection of styles. It was renamed with deprecation.