refactor: rename app from ncdiscordhook to nc_bot_webhooks

- Update namespace from OCA\NCdiscordhook to OCA\Ncbotwebhooks
- Update app ID, name, and namespace in appinfo/info.xml
- Update composer.json and autoload files
- Update CLI command names from ncdiscordhook:* to nc_bot_webhooks:*
- Update image directory name to nc_bot_webhooks-images
- Update documentation in README.md and INSTALL.md
- Update JavaScript APP_ID and navigation provider paths
- Update admin settings and controller app references

appinfo/cron.php

@@ -1,6 +1,6 @@
 <?php
 return [
     'jobs' => [
-        \OCA\NCdiscordhook\Cron\ImageCleanup::class,
+        \OCA\Ncbotwebhooks\Cron\ImageCleanup::class,
     ],
 ];