Fix additional missing API doc tags.
Make PHPCS build passing again.
Update code examples to be consistent with other docs.
Remove mention of Role/default as it doesn't exist.

The default role merging was removed in
3abfaeecf30b845ac3a309f011bc460222a923b4 and shouldn't be mentioned in
the docs.

Fixes #3871
Correct doc blocks according to cs guidelines.
Remove superfluous empty lines.