Move ctag section to "Suggested Workflow"

Author: andoriyu

src/building/suggested.md

@@ -71,6 +71,34 @@ Task] instead:
 
 [Build Task]: https://code.visualstudio.com/docs/editor/tasks
 
+
+## Configuring `ctags`
+
+One of the challenges with rustc is that the RLS can't handle it, since it's a
+bootstrapping compiler. This makes code navigation difficult. One solution is to
+use `ctags`.
+
+`ctags` has a long history and several variants. Exuberant Ctags seems to be
+quite commonly distributed but it does not have out-of-box Rust support. Some
+distributions seem to use [Universal Ctags][utags], which is a maintained fork
+and does have built-in Rust support.
+
+The following script can be used to set up Exuberant Ctags:
+[https://github.com/nikomatsakis/rust-etags][etags].
+
+`ctags` integrates into emacs and vim quite easily. The following can then be
+used to build and generate tags:
+
+```console
+$ rust-ctags src/lib* && ./x.py build <something>
+```
+
+This allows you to do "jump-to-def" with whatever functions were around when
+you last built, which is ridiculously useful.
+
+[etags]: https://github.com/nikomatsakis/rust-etags
+[utags]: https://github.com/universal-ctags/ctags
+
 ## Check, check, and check again
 
 When doing simple refactorings, it can be useful to run `./x.py check`