Add Definition of a transformer to the glossary
Thought it may be helpful to have an easy to understand definition for what a transformer is in the [glossary](https://huggingface.co/transformers/glossary.html) for any new joiners.

@sgugger any thoughts?

Happy to add a definition if provided with one in the open pull request #8949
Are you looking for https://huggingface.co/transformers/model_summary.html ?<|||||>@cronoik thanks for taking a look! Wasn't looking for that page, was trying to find just a general definition of what a transformer is in terms of the general concept<|||||>Do you have something like this in mind: https://github.com/huggingface/transformers/blob/master/notebooks/02-transformers.ipynb ?<|||||>No, wasn't looking for a notebook, just a one line description/explanation of what a transformer is

How would you describe it to someone who doesn't know about transformers?<|||||>Maybe simply as self-attention based deep learning model architecture.<|||||>@cronoik That's a good start, `self-attention` & `deep learning` aren't yet defined in the glossary

How would you define those?<|||||>`self-attention`: each element of the input finds out which other elements of the input they should attend to.
`deep learning`: machine learning algorithms which uses NN which several layers.

@darigovresearch <|||||>@cronoik thanks for that! Would you like to put in a pull request so that your definitions go into the transformers glossary and the set of flashcards that we built or would you like us to do it?

I'm sure those definitions would be welcome and easily merged by the maintainers

https://www.darigovresearch.com/huggingface-transformers-glossary-flashcards<|||||>Thanks @sgugger for merging the pull request, @cronoik your definitions are now on the glossary page and I have also added them to the flashcards so this issue can now be closed. Thank you both for your help!

Glossary https://huggingface.co/transformers/glossary.html

Flashcards https://www.darigovresearch.com/huggingface-transformers-glossary-flashcards<|||||>Thanks for your commits ;).