[Doc] Improve rust analyzer section, distinguishing bzlmod and WORKSPACE

Author: Alessandro Bertulli

Diff for: docs/rust_analyzer.vm

@@ -8,23 +8,46 @@ such a file.
 
 ### Setup
 
+#### Bzlmod
+
 First, ensure `rules_rust` is setup in your workspace. By default, `rust_register_toolchains` will
 ensure a [rust_analyzer_toolchain](#rust_analyzer_toolchain) is registered within the WORKSPACE.
 
 Next, load the dependencies for the `rust-project.json` generator tool:
 
 ```python
+# BUILD.bazel
+
 load("@rules_rust//tools/rust_analyzer:deps.bzl", "rust_analyzer_dependencies")
+```
 
-rust_analyzer_dependencies()
+Bazel will create the target `@rules_rust//tools/rust_analyzer:gen_rust_project`, which you can build
+with
+
+```
+bazel run @rules_rust//tools/rust_analyzer:gen_rust_project
 ```
 
-Finally, run `bazel run @rules_rust//tools/rust_analyzer:gen_rust_project`
 whenever dependencies change to regenerate the `rust-project.json` file. It
 should be added to `.gitignore` because it is effectively a build artifact.
 Once the `rust-project.json` has been generated in the project root,
 rust-analyzer can pick it up upon restart.
 
+#### WORKSPACE
+
+As with Bzlmod, ensure `rules_rust` is setup in your workspace.
+
+Moreover, when loading the dependencies for the tool, you should call the function `rust_analyzer_dependencies()`:
+
+```python
+load("@rules_rust//tools/rust_analyzer:deps.bzl", "rust_analyzer_dependencies")
+
+rust_analyzer_dependencies()
+```
+
+Again, you can now run `bazel run @rules_rust//tools/rust_analyzer:gen_rust_project`
+whenever dependencies change to regenerate the `rust-project.json` file.
+
 For users who do not use `rust_register_toolchains` to register toolchains, the following can be added
 to their WORKSPACE to register a `rust_analyzer_toolchain`. Please make sure the Rust version used in
 this toolchain matches the version used by the currently registered toolchain or the sources/documentation