Rollup merge of #145842 - tshepang:rdg-sync, r=jieyouxu

rustc-dev-guide subtree update

Subtree update of `rustc-dev-guide` to a03c1ef.

Created using https://github.com/rust-lang/josh-sync.

r? `@ghost`

Author: Zalathar

rust-version

@@ -1 +1 @@
-425a9c0a0e365c0b8c6cfd00c2ded83a73bed9a0
+a1dbb443527bd126452875eb5d5860c1d001d761

src/SUMMARY.md

@@ -103,6 +103,7 @@
 	- [The `rustdoc-json` test suite](./rustdoc-internals/rustdoc-json-test-suite.md)
 - [GPU offload internals](./offload/internals.md)
     - [Installation](./offload/installation.md)
+    - [Usage](./offload/usage.md)
 - [Autodiff internals](./autodiff/internals.md)
     - [Installation](./autodiff/installation.md)
     - [How to debug](./autodiff/debugging.md)

src/building/bootstrapping/what-bootstrapping-does.md

@@ -23,7 +23,7 @@ Note that this documentation mostly covers user-facing information. See
 
 ### Overview
 
-- Stage 0: the pre-compiled compiler
+- Stage 0: the pre-compiled compiler and standard library
 - Stage 1: from current code, by an earlier compiler
 - Stage 2: the truly current compiler
 - Stage 3: the same-result test
@@ -192,7 +192,7 @@ include, but are not limited to:
   artifacts'). If you're working on the standard library, this is normally the
   test command you want.
 - `./x build --stage 0` means to build with the stage0 `rustc`.
-- `./x doc --stage 0` means to document using the stage0 `rustdoc`.
+- `./x doc --stage 1` means to document using the stage0 `rustdoc`.
 
 #### Examples of what *not* to do
 
@@ -211,7 +211,7 @@ include, but are not limited to:
 In short, _stage 0 uses the `stage0` compiler to create `stage0` artifacts which
 will later be uplifted to be the stage1 compiler_.
 
-In each stage, two major steps are performed:
+In each stage besides 0, two major steps are performed:
 
 1. `std` is compiled by the stage N compiler.
 2. That `std` is linked to programs built by the stage N compiler, including the