Update .cargo/config guide in the book
The .cargo/config snippet in the book was missing
a line without which the build gave an error
`error: Unresolved symbol "memcmp"`
@@ -58,7 +58,7 @@ const SHADER: &[u8] = include_bytes!(env!("<shader_name>.spv"));
> **Note** This method will require manually rebuilding `rust-gpu` each
time there has been changes to the repository.
-If you just want to compile a build a shader crate, and don't need to
+If you just want to build a shader crate, and don't need to
automatically compile the SPIR-V binary at build time, you can use
`.cargo/config` to set the necessary flags. Before you can do that however you
need to do a couple of steps first to build the compiler backend.
@@ -86,6 +86,7 @@ rustflags = [
[unstable]
build-std=["core"]
+build-std-features=["compiler-builtins-mem"]
```
Now we can build our crate with cargo as normal.
