[Content Addition] General prerequisites page

[CrackTheCode016]

Does this address existing content?

Partially, as it will provide a consistent reference for dependencies that existing content can utilize.

What should be added? If this is independent of existing content, what is the suggested list of material to cover?

A general "Course Prerequisites" page that dictates the tools one should have on their system, something along the lines of:

• Rust/rustc/cargo etc
• Polkadot 1.0 (?)
• Recommended specs, especially when it comes to compiling templates

This page, or section, should also contain instructions with how to install these for multiple platforms.