Update the name tags tutorial to include Tag elements

We should update this tutorial

https://training.galaxyproject.org/training-material/topics/galaxy-interface/tutorials/name-tags/tutorial.html

to include the Tag elements tool.

We could even just cross link to the example in the tag-based analysis approach in this tutorial section

https://training.galaxyproject.org/training-material/topics/transcriptomics/tutorials/ref-based/tutorial.html#hands-on-choose-your-own-tutorial-1

Or, abstract into a snippet? Open to ideas. We do have an FAQ here but it doesn't mention the dedicated tool either. Maybe putting all of these together is the solution.

https://training.galaxyproject.org/training-material/faqs/galaxy/datasets_add_tag.html

What do you think @mvdbeek ?

This came up in Q&A at the forum, see https://help.galaxyproject.org/t/14708/4

Start with the name-tags tutorial at topics/galaxy-interface/tutorials/name-tags/tutorial.html and compare the Tag elements example in the ref-based tutorial. Review the datasets_add_tag FAQ as well. Done means the name tags tutorial explains or links to the Tag elements tool, with the related FAQ and example handled consistently after the proposed approach is agreed.

Written by the indexing model from the issue text.