Parametrizations tutorial (pytorch#1444)

* Parametrizaitons tutorial

* Add remove_parametrization

* Correct name

* minor

* Proper version number

* Fuzzy spellcheck

* version

* Remove _tutorial from name

* Forgot to add the file...

* Rename parametrizations_tutorial by parametrizations everywhere
Add Alban's suggestions
Correct the code
Beter spacing after enumeration

* Minor

* Add more comments

* Minor

* Prefer unicode over math

* Minor

* minor

* Corrections

Co-authored-by: Brian Johnson <brianjo@fb.com>

index.rst

@@ -324,6 +324,13 @@ Welcome to PyTorch Tutorials
    :link: beginner/hyperparameter_tuning_tutorial.html
    :tags: Model-Optimization,Best-Practice
 
+.. customcarditem::
+   :header: Parametrizations Tutorial
+   :card_description: Learn how to use torch.nn.utils.parametrize to put constriants on your parameters (e.g. make them orthogonal, symmetric positive definite, low-rank...)
+   :image: _static/img/thumbnails/cropped/parametrizations.png
+   :link: intermediate/parametrizations.html
+   :tags: Model-Optimization,Best-Practice
+
 .. customcarditem::
    :header: Pruning Tutorial
    :card_description: Learn how to use torch.nn.utils.prune to sparsify your neural networks, and how to extend it to implement your own custom pruning technique.
@@ -620,6 +627,7 @@ Additional Resources
 
    beginner/profiler
    beginner/hyperparameter_tuning_tutorial
+   intermediate/parametrizations
    intermediate/pruning_tutorial
    advanced/dynamic_quantization_tutorial
    intermediate/dynamic_quantization_bert_tutorial