add sample Makefile

Makefile.sample

@@ -0,0 +1,17 @@
+
+PACKAGES := io image net net/http bufio reflect net/rpc go/ast os mime/multipart regexp/syntax
+
+all: $(addsuffix .png, $(PACKAGES))
+
+.PRECIOUS: %.puml
+
+godoc2puml: FORCE
+	go build
+
+%.puml: godoc2puml FORCE
+	./godoc2puml $* >  $(subst /,.,$*).puml
+
+%.png: %.puml
+	java -jar plantuml.jar -pipe -tpng < $(subst /,.,$*).puml > $(subst /,.,$*).png
+
+FORCE:

README.md

@@ -16,7 +16,7 @@ If you want to draw a diagram as a image file, it depends on java and graphviz.
     $ # or, etc...
     $ sudo apt-get install java graphviz
 
-It also depends on plantuml. Well, it is already attached so you do not need to install separately.
+It also depends on plantuml. <del>Well, it is already attached so you do not need to install separately.</del>
 
 Usage
 -----
@@ -52,6 +52,7 @@ Many, but...
 * elementType of map is not recognized as an association
 * relations of embed struct are not recognized properly
 * interface extensions is recognized only when explicit extensions, not implicit extension
+* cant handle build constraints tag
 * ...
 
 References