Use site-functions directory for all zsh plugins

zsh/_open

@@ -0,0 +1,12 @@
+#compdef open
+
+# ========== Completions ==========
+local arguments
+
+arguments=(
+  {-d,--dir}'[select a directory to search in]'
+  {-h,--help}'[show this help page]'
+  '*:filename:_files'
+)
+
+_arguments -s $arguments