reorg preface

Makefile

@@ -8,7 +8,7 @@ build/%.md: %.md
 	@mkdir -p $(@D)
 	@cp $< $@
 
-MARKDOWN = $(filter-out chapter_preface/notation.md, $(wildcard chapter_preface/*.md */index.md) chapter_appendix/install.md)
+MARKDOWN = $(filter-out chapter_preface/notation.md, $(wildcard chapter_preface/*.md */index.md) chapter_crashcourse/install.md)
 NOTEBOOK = $(filter-out $(MARKDOWN), $(wildcard chapter*/*.md))
 
 OBJ = $(patsubst %.md, build/%.md, $(MARKDOWN)) \

chapter_appendix/index.md

@@ -5,8 +5,6 @@
 .. toctree::
    :maxdepth: 2
 
-   install
-   buy-gpu
-   aws
    math
+   buy-gpu
 ```

chapter_crashcourse/index.md

@@ -6,6 +6,8 @@
    :maxdepth: 2
 
    introduction
+   install
+   aws
    ndarray
    autograd