Auto merge of #39633 - steveklabnik:vendor-mdbook, r=alexcrichton

Port books to mdbook

Part of #39588

blocked on #39431

As a first step towards the bookshelf, we ~vendor mdbook in-tree and~ port our books to it. Eventually, both of these books will be moved out-of-tree, but the nightly book will rely on doing the same thing. As such, this intermediate step is useful.

r? @alexcrichton @brson

/cc @azerupi

.gitattributes

@@ -6,4 +6,4 @@
 *.rs rust
 src/etc/installer/gfx/* binary
 *.woff binary
-src/vendor/* binary
+src/vendor/** -text

.gitignore

@@ -100,3 +100,4 @@ version.md
 version.ml
 version.texi
 .cargo
+!src/vendor/**

src/bootstrap/doc.rs

@@ -47,6 +47,7 @@ pub fn rustbook(build: &Build, target: &str, name: &str) {
     build.run(build.tool_cmd(&compiler, "rustbook")
                    .arg("build")
                    .arg(&src)
+                   .arg("-d")
                    .arg(out));
 }
 

src/doc/book/README.md → src/doc/book/src/README.md

@@ -1,4 +1,4 @@
-% The Rust Programming Language
+# The Rust Programming Language
 
 Welcome! This book will teach you about the [Rust Programming Language][rust].
 Rust is a systems programming language focused on three goals: safety, speed,

src/doc/book/SUMMARY.md → src/doc/book/src/SUMMARY.md

@@ -1,5 +1,7 @@
 # Summary
 
+[Introduction](README.md)
+
 * [Getting Started](getting-started.md)
 * [Tutorial: Guessing Game](guessing-game.md)
 * [Syntax and Semantics](syntax-and-semantics.md)

src/doc/book/advanced-linking.md → src/doc/book/src/advanced-linking.md

@@ -1,4 +1,4 @@
-% Advanced Linking
+# Advanced Linking
 
 The common cases of linking with Rust have been covered earlier in this book,
 but supporting the range of linking possibilities made available by other

src/doc/book/associated-constants.md → src/doc/book/src/associated-constants.md

@@ -1,4 +1,4 @@
-% Associated Constants
+# Associated Constants
 
 With the `associated_consts` feature, you can define constants like this:
 

src/doc/book/associated-types.md → src/doc/book/src/associated-types.md

@@ -1,4 +1,4 @@
-% Associated Types
+# Associated Types
 
 Associated types are a powerful part of Rust’s type system. They’re related to
 the idea of a ‘type family’, in other words, grouping multiple types together. That

src/doc/book/attributes.md → src/doc/book/src/attributes.md

@@ -1,4 +1,4 @@
-% Attributes
+# Attributes
 
 Declarations can be annotated with ‘attributes’ in Rust. They look like this:
 

src/doc/book/benchmark-tests.md → src/doc/book/src/benchmark-tests.md

@@ -1,4 +1,4 @@
-% Benchmark tests
+# Benchmark tests
 
 Rust supports benchmark tests, which can test the performance of your
 code. Let's make our `src/lib.rs` look like this (comments elided):

src/doc/book/bibliography.md → src/doc/book/src/bibliography.md

@@ -1,4 +1,4 @@
-% Bibliography
+# Bibliography
 
 This is a reading list of material relevant to Rust. It includes prior
 research that has - at one time or another - influenced the design of