CI: Change doc generation to use a more generic target

.github/workflows/docs.yml

@@ -44,9 +44,9 @@ jobs:
         working-directory: zephyr-lang-rust
         run: |
           # Note that the above build doesn't set Zephyrbase, so we'll need to do that here.
-          west build -t rustdoc -b nrf52840dk/nrf52840 docgen
+          west build -t rustdoc -b qemu_cortex_m3 docgen
           mkdir rustdocs
-          mv build/rust/target/thumbv7em-none-eabi/doc rustdocs/nostd
+          mv build/rust/target/thumbv7m-none-eabi/doc rustdocs/nostd
           cp docs/top-index.html rustdocs/index.html
 
       - name: Build build documentation

zephyr/src/sys/thread.rs

@@ -233,6 +233,8 @@ impl Thread {
     /// Safe use follows similar requirements to using this safely from within C code.  Passing Rust
     /// values through this interface is difficult to get right, and it is generally recommended to
     /// use [`spawn`].
+    ///
+    /// [`spawn`]: Self::spawn
     pub unsafe fn simple_spawn(
         mut self,
         child: k_thread_entry_t,