Remove reference to the Rust Game-of-Life book.

The rustwasm GitHub org is being sunsetted:
https://blog.rust-lang.org/inside-rust/2025/07/21/sunsetting-the-rustwasm-github-org/

Author: youngman-g

docs/getting-started.md

@@ -29,27 +29,19 @@ web server.  The simulator doesn't execute on the server.
 
 #### Installing the WASM Toolchain
 
-These instructions are based on the [Rust Game-of-Life WASM
-book](https://rustwasm.github.io/docs/book/game-of-life/setup.html).
-If these instructions seem not to work then please [raise a
-bug](https://github.com/TX-2/TX-2-simulator/issues/new/choose) but
-meanwhile you might be about to figure out the problem by looking at
-the [Rust Game-of-Life WASM
-book](https://rustwasm.github.io/docs/book/game-of-life/setup.html)
-
-#### Toolchain Installation Steps
-
 1. Follow the instructions above to install the Rust
    toolchain.
-1. Install wasm-pack by either [following these scary `curl | sh`
-   instructions](https://rustwasm.github.io/wasm-pack/installer/) or
-   by using `cargo install wasm-pack`.
+1. Install wasm-pack with `cargo install wasm-pack`.
 1. [Install npm](https://docs.npmjs.com/getting-started).
-1. If you already have `npm` install, make sure it is up-to-date by
+1. If you already have `npm` installed, make sure it is up-to-date by
    running `npm install npm@latest -g`
 
 You should not need `cargo-generate`.
 
+If these instructions seem not to work then please [raise a
+bug](https://github.com/TX-2/TX-2-simulator/issues/new/choose).
+
+
 ## Building the Code
 
 While it is possible to build just the CLI components (the CLI-based