wording way too relaxed about not installing cargo generate

[flip111]

https://rust-embedded.github.io/book/intro/tooling.html

[OPTIONAL] git OR cargo-generate. If you have neither installed then don't worry about installing either.

Big fat OPTIONAL and don't worry. Later https://rust-embedded.github.io/book/start/qemu.html#a-non-standard-rust-program it's required to follow the book because at that point no alternative is provided.

Suggestion 1:

cargo-generate and git. This is optional for embedded programming with rust but needed to follow along with the book.

Suggestion 2:
provide install command for cargo-generate here https://rust-embedded.github.io/book/intro/install.html also point to git website