add custom plugins

lua/custom/plugins/vim-helm.lua

@@ -0,0 +1,10 @@
+-- You can add your own plugins here or in other files in this directory!
+--  I promise not to create any merge conflicts in this directory :)
+--
+-- See the kickstart.nvim README for more information
+return {
+  {
+    'towolf/vim-helm',
+    ft = 'helm',
+  },
+}