Add dimensonality terms to glossary

[canyon289]

Description of your problem

The dimensionality notebook contains numerous terms that would benefit from additional to the glossary and crosslinking across sphinx. Scope of ticket is in quote below

We could include those in the glossary and here so that when they appear somewhere else we can use term role and render it as a link to its glossary definition

References
#5437
https://github.com/pymc-devs/pymc/blob/main/docs/source/learn/examples/dimensionality.ipynb

[soma2000-lang]

@canyon289 can i work on this

[canyon289]

of course!

[canyon289]

@soma2000-lang assigned to you. Let us know if you need help

[OriolAbril]

@canyon289 not sure this is available, @mjhajharia added this to the "Being worked on" column of the sprint project.

@soma2000-lang iirc you have already a couple other issues assigned. Let us know if you are having any trouble with them or finding a suitable issue and we'll do our best to help. Not saying you should not work on this if it's available, only making sure you know you can ask questions here if you needed it. I remember it was quite difficult for me when I started to find suitable issues