docs: Add Notes page

[critesjosh]

Add a page to the docs about Notes (to the Foundational Concepts section, or after Storage in dev docs?).

Be sure to include information about the best way to add info about a note that is created in a public function to the PXE. See this e2e test for an example of how this is done with the TransparentNote in the token contract example.

• everything from how to use, create, destroy
• explanations of interfaces and functions
• understanding storage from the context of notes

[critesjosh]

related issue #2914

[jzaki]

• Surrounding knowledge on storage trees, create/read/nullify, use in pxe, tx execution,
• [ ] Coding example(s)
• Draft content
• put in docs

[critesjosh]

I am thinking this page should be more of an explainer than a how to or a guide. What are you thinking?