feat: _ command for nushell for retrieving the last command

modules/common/nushell/config.nu

@@ -158,8 +158,14 @@ $env.config.cursor_shape = {
 
 $env.config.hooks = {
   command_not_found: {||}
-  display_output:    "table --expand"
+
+  display_output: {
+    tee { table --expand | print }
+    | $env.last = $in
+  }
+
   env_change: {}
+
   pre_execution: [
     {
       let prompt = commandline | str trim
@@ -171,9 +177,15 @@ $env.config.hooks = {
       print $"(ansi title)($prompt) — nu(char bel)"
     }
   ]
+
   pre_prompt: []
 }
 
+# Retrieve the output of the last command.
+def _ []: nothing -> any {
+  $env.last
+}
+
 $env.config.menus = [
   {
     marker:                 "| "