Missing env command in docs sidebar (#715)

## Description

Adds `corso env` auto-gen command docs to docs sidebar. 

## Type of change

Please check the type of change your PR introduces:
- [ ] 🌻 Feature
- [x] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Test
- [ ] 🐹 Trivial/Minor

## Issue(s)

## Test Plan

<!-- How will this be tested prior to merging.-->

- [x] 💪 Manual
- [ ] ⚡ Unit test
- [ ] 💚 E2E

docs/sidebars.js

@@ -28,7 +28,7 @@ const sidebars = {
       items: [
         'cli/corso_repo_init_s3', 'cli/corso_repo_connect_s3', 
         'cli/corso_backup_create_exchange', 'cli/corso_backup_list_exchange', 'cli/corso_backup_details_exchange',
-        'cli/corso_restore_exchange',
+        'cli/corso_restore_exchange', 'cli/corso_env'
       ]
     }, 
     {