Fix dead links in the guide and reorganize

Author: alexcrichton

mk/docs.mk

@@ -275,9 +275,8 @@ endif
 docs: $(DOC_TARGETS)
 compiler-docs: $(COMPILER_DOC_TARGETS)
 
-trpl: tmp/trpl.ok
+trpl: doc/book/index.html
 
-tmp/trpl.ok: $(RUSTBOOK_EXE) $(wildcard $(S)/src/doc/trpl/*.md)
+doc/book/index.html: $(RUSTBOOK_EXE) $(wildcard $(S)/src/doc/trpl/*.md)
 	$(Q)rm -rf doc/book
 	$(Q)$(RUSTBOOK) build $(S)src/doc/trpl doc/book
-	$(Q)touch $@

mk/tests.mk

@@ -156,8 +156,8 @@ endef
 
 $(foreach doc,$(DOCS), \
   $(eval $(call DOCTEST,md-$(doc),$(S)src/doc/$(doc).md)))
-$(foreach file,$(wildcard $(S)src/doc/trpl/src/*), \
-  $(eval $(call DOCTEST,$(file:$(S)src/doc/trpl/src/%.md=trpl-%),$(file))))
+$(foreach file,$(wildcard $(S)src/doc/trpl/*.md), \
+  $(eval $(call DOCTEST,$(file:$(S)src/doc/trpl/%.md=trpl-%),$(file))))
 
 ######################################################################
 # Main test targets