Comprehensive Rust v2 (#1073)

I've taken some work by @fw-immunant and others on the new organization
of the course and condensed it into a form amenable to a text editor and
some computational analysis. You can see the inputs in `course.py` but
the interesting bits are the output: `outline.md` and `slides.md`.

The idea is to break the course into more, smaller segments with
exercises at the ends and breaks in between. So `outline.md` lists the
segments, their duration, and sums those durations up per-day. It shows
we're about an hour too long right now! There are more details of the
segments in `slides.md`, or you can see mostly the same stuff in
`course.py`.

This now contains all of the content from the v1 course, ensuring both
that we've covered everything and that we'll have somewhere to redirect
every page.

Fixes #1082.
Fixes #1465.

---------

Co-authored-by: Nicole LeGare <dlegare.1001@gmail.com>
Co-authored-by: Martin Geisler <mgeisler@google.com>

mdbook-course/src/replacements.rs

@@ -0,0 +1,61 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use crate::course::{Course, Courses, Segment, Session};
+use mdbook::book::Chapter;
+use regex::Regex;
+
+lazy_static::lazy_static! {
+    static ref DIRECTIVE: Regex = Regex::new(r#"\{\{%([^}]*)}}"#).unwrap();
+}
+
+/// Replace supported directives with the relevant content.
+///
+/// See the mdbook-course README for details.
+#[allow(unused_variables)]
+pub fn replace(
+    courses: &Courses,
+    course: Option<&Course>,
+    session: Option<&Session>,
+    segment: Option<&Segment>,
+    chapter: &mut Chapter,
+) {
+    let Some(source_path) = &chapter.source_path else {
+        return;
+    };
+    chapter.content = DIRECTIVE
+        .replace(&chapter.content, |captures: &regex::Captures| {
+            let directive_str = captures[1].trim();
+            let directive: Vec<_> = directive_str.split_whitespace().collect();
+            match directive.as_slice() {
+                ["session", "outline"] if session.is_some() => {
+                    session.unwrap().outline(source_path)
+                }
+                ["segment", "outline"] if segment.is_some() => {
+                    segment.unwrap().outline(source_path)
+                }
+                ["course", "outline"] if course.is_some() => {
+                    course.unwrap().schedule(source_path)
+                }
+                ["course", "outline", course_name] => {
+                    let Some(course) = courses.find_course(course_name) else {
+                        return captures[0].to_string();
+                    };
+                    course.schedule(source_path)
+                }
+                _ => directive_str.to_owned(),
+            }
+        })
+        .to_string();
+}