Move x.py commands to overview

Author: jyn514

src/rustdoc-internals.md

@@ -192,6 +192,3 @@ runtime. These tests don't have as thorough of a writeup, but a broad example
 that features results in all tabs can be found in `basic.js`. The basic idea is
 that you match a given `QUERY` with a set of `EXPECTED` results, complete with
 the full item path of each item.
-
-You can run tests using the name of the folder. For example,
-`x.py test --stage 1 src/test/rustdoc` will run the output tests using a stage1 rustdoc.

src/rustdoc.md

@@ -41,6 +41,8 @@ does is call the `main()` that's in this crate's `lib.rs`, though.)
   * The completed docs will be available in `build/$TARGET/doc/std`, though the
     bundle is meant to be used as though you would copy out the `doc` folder to
     a web server, since that's where the CSS/JS and landing page are.
+* Use `x.py test --stage 1 src/test/rustdoc*` to run the tests using a stage1 rustdoc.
+  * See [rustdoc internals] for more information about tests.
 * Most of the HTML printing code is in `html/format.rs` and `html/render.rs`.
   It's in a bunch of `fmt::Display` implementations and supplementary
   functions.
@@ -58,4 +60,6 @@ does is call the `main()` that's in this crate's `lib.rs`, though.)
 
 ## See also
 
-For more details about how rustdoc works, see the page on [rustdoc internals](./rustdoc-internals.md).
+For more details about how rustdoc works, see the page on [rustdoc internals].
+
+[rustdoc internals]: ./rustdoc-internals.md