Categorize items in README

[strivn]

Resource Addition

Category

N/A

Description

Simple categorization that I could think of for now. Design considerations:

• I was thinking to make it less 'cluttered' on first glance, so I used expanding sections. But at the same time, I want to ensure people don't have to put additional effort to look at resources. So for FL (which is the main focus, presumably, and where we have most resources) I made it open by default.
• I'm thinking of separating another section of "beginner friendly" resources too, but this may need further curation. I think it'd be really helpful for people who are just starting out (e.g. Google Comic, Zama's Intro, etc).

Checklist

• I have followed the contribution guidelines
• The resource is freely accessible (or marked if paid)
• I have added it to the appropriate category
• The link is functional
• The description is clear and concise

[strivn]

For how it may look like on github: https://github.com/strivn/30DaysOfFLCode-1/tree/main

[leriomaggio]

Love this and thanks very much for putting this together.

I would just work a little better on categories (E.g. FL section also contains resources about DP).

Can you please iterate on that again?
Also, I would keep tools out of the equations and maybe having them listed on top as first thing. Especially for tools like SyftBox who are supporting multiple PETs by design :)

[strivn]

New related PR: #36