update README

Makefile

@@ -11,7 +11,16 @@ ${BIN}: ${SRC}
 test:
 	go test ./...
 
+api:
+	@sed '/^## API$$/,$$d' -i README.md
+	@echo '## API' >> README.md
+	@godoc2md github.com/studio-b12/gowebdav | sed '/^$$/N;/^\n$$/D' |\
+	sed '2d' |\
+	sed 's/\/src\/github.com\/studio-b12\/gowebdav\//https:\/\/github.com\/studio-b12\/gowebdav\/blob\/master\//g' |\
+	sed 's/\/src\/target\//https:\/\/github.com\/studio-b12\/gowebdav\/blob\/master\//g' |\
+	sed 's/^#/##/g' >> README.md
+
 clean:
 	@rm -f ${BIN}
 
-.PHONY: all cmd clean test
+.PHONY: all cmd clean test api