Cookbook: add an example of using default.do for text processing.

mkdocs.yml

@@ -11,6 +11,7 @@ pages:
   - Getting Started: GettingStarted.md
   - Cookbook:
     - Hello World: cookbook/hello.md
+    - Using default.do (text processing): cookbook/defaults.md
   - FAQ:
     - Basics: FAQBasics.md
     - Semantics: FAQSemantics.md
@@ -18,15 +19,14 @@ pages:
     - Parallel Builds: FAQParallel.md
     - Implementation Details: FAQImpl.md
   - Contributing.md
-  - Reference:
-    - Manual Pages:
-      - redo: redo.md
-      - redo-ifchange: redo-ifchange.md
-      - redo-ifcreate: redo-ifcreate.md
-      - redo-always: redo-always.md
-      - redo-stamp: redo-stamp.md
-      - redo-sources: redo-sources.md
-      - redo-targets: redo-targets.md
-      - redo-ood: redo-ood.md
-      - redo-whichdo: redo-whichdo.md
-      - redo-log: redo-log.md
+  - Reference Manual:
+    - redo(1): redo.md
+    - redo-ifchange(1): redo-ifchange.md
+    - redo-ifcreate(1): redo-ifcreate.md
+    - redo-always(1): redo-always.md
+    - redo-stamp(1): redo-stamp.md
+    - redo-sources(1): redo-sources.md
+    - redo-targets(1): redo-targets.md
+    - redo-ood(1): redo-ood.md
+    - redo-whichdo(1): redo-whichdo.md
+    - redo-log(1): redo-log.md