Revert "nvim: lua: plugins: Remove post install hook for fzf"

This reverts commit aba40d88df and also
fixes the post install hook command.

Original issue:
https://github.com/wbthomason/packer.nvim/issues/83

Fixed by:
6f9efb232a

nvim/.config/nvim/lua/plugins.lua

@@ -10,7 +10,10 @@ local init = function ()
     config = "require('modules.sneak')"
   }
   -- Search
-  use 'junegunn/fzf'
+  use {
+    'junegunn/fzf',
+    run = './install --bin'
+  }
   use {
     'junegunn/fzf.vim',
     config = "require('modules.fzf')"