update

.rc.func.sh

@@ -139,3 +139,7 @@ function gitarchive() {
     second=`git log -2 --pretty=oneline | cut -d ' ' -f 1 | tail -n 1`
     git archive -o $1 $first $(git diff --name-only $second $first)
 }
+
+function installyarn() {
+    npm install --global yarn
+}