Add hooks to cli/repl (#5479)

* Add hooks to cli/repl

* Clippy

* Clippy

docs/sample_config/default_config.nu

@@ -199,6 +199,14 @@ let-env config = {
   shell_integration: true # enables terminal markers and a workaround to arrow keys stop working issue
   disable_table_indexes: false # set to true to remove the index column from tables
   cd_with_abbreviations: false # set to true to allow you to do things like cd s/o/f and nushell expand it to cd some/other/folder
+  hooks: {
+    pre_prompt: {
+      $nothing  # replace with source code to run before the prompt is shown 
+    }
+    pre_execution: {
+      $nothing  # replace with source code to run before the repl input is run
+    }
+  }
   menus: [
       # Configuration for default nushell menus
       # Note the lack of souce parameter