Add Cargo links

Fix the order of footnotes to reflect their appearance in the document.

rust-intro.org

@@ -482,6 +482,8 @@
    - [[https://doc.rust-lang.org/cargo/index.html][The Cargo Book]] (~$ rustup docs --cargo~)
    - Guillaume Gomez: [[https://blog.guillaume-gomez.fr/articles/2020-03-12+Guide+on+how+to+write+documentation+for+a+Rust+crate][Guide on how to write documentation for a Rust
      crate]]
+   - [[https://crates.io/policies][Policies]]
+   - [[https://crates.io/category_slugs][Category Slugs]]
 
 ** Cargo commands/plugins
 *** What I typically use
@@ -696,8 +698,8 @@
 [fn:rust_fungus] [[https://commons.wikimedia.org/wiki/File:Bruine_roest_op_tarwe_(Puccinia_recondita_f.sp._tritici_on_Triticum_aestivum).jpg][Wikimedia]]
 [fn:strengths] Copied list from: [[https://cheats.rs/#tab-hello-3][cheats.rs]].
 [fn:weaknesses] Copied list from: [[https://cheats.rs/#tab-hello-4][cheats.rs]].
-[fn:gcc] Work on GCC: [[https://rust-gcc.github.io/][rust-gcc]] and [[https://news.ycombinator.com/item?id=27775544][gcc rust backend]].
 [fn:lwn_gcc] [[https://lwn.net/Articles/871283/][Rust and GCC, two different ways]]
+[fn:gcc] Work on GCC: [[https://rust-gcc.github.io/][rust-gcc]] and [[https://news.ycombinator.com/item?id=27775544][gcc rust backend]].
 [fn:survey] [[https://blog.rust-lang.org/2020/04/17/Rust-survey-2019.html#why-not-use-rust][Rust survey]]
 [fn:compiler_speed] [[https://news.ycombinator.com/item?id=23538220][The Rust compiler isn't slow; we are]]
 [fn:specification] [[https://people.mpi-sws.org/%7Ejung/thesis.html][Understanding and Evolving the Rust Programming Language]]