docs: rust: add command line to rust-analyzer section

Add command line to rust-analyzer section for convenience purposes.

Signed-off-by: Guillaume Plourde <gplourde@protonmail.com>
Link: https://lore.kernel.org/r/y4jBalhfESeCZDShmVaGwrdlIRoIHroqNVUUYLck6qGNwB5e7wbIJO5DoiLBTPpTNYtdneWRODjhXwlIl9VzokqxffdNU7y__1wIa7BBl94=@protonmail.com
[ Fixed indentation to tab and reworded title. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: Perpixel

Documentation/rust/quick-start.rst

@@ -196,7 +196,9 @@ be used with many editors to enable syntax highlighting, completion, go to
 definition, and other features.
 
 ``rust-analyzer`` needs a configuration file, ``rust-project.json``, which
-can be generated by the ``rust-analyzer`` Make target.
+can be generated by the ``rust-analyzer`` Make target::
+
+	make LLVM=1 rust-analyzer
 
 
 Configuration