LRDOCS-1390 created tutorial that explains how to use the Liferay-UI:tabs tag.
LRDOCS-1390 Added screenshots for the tutorial.
LRDOCS-1390 Updated attribute definitions.
LRDOCS-1390 Numbered header.
LRDOCS-1390 Made edits.
LRDOCS-1390 Edits
Merge branch 'LRDOCS-1390' of https://github.com/mwilliams2014/liferay-docs into LRDOCS-1390-R