add zsh.snippets, add getopts snippet

vim/UltiSnips/zsh.snippets

@@ -0,0 +1,18 @@
+snippet getopts "Deal with shell parameters" b
+BOOL=false
+VAVLUE=''
+while getopts ":bv:" o; do
+  case "${o}" in
+    b)
+      BOOL=true
+      ;;
+    v)
+      VALUE=${OPTARG}
+      ;;
+    *)
+      echo "Usage: $1 [-b] [-v VALUE]"
+      return
+      ;;
+  esac
+done
+endsnippet