fix: correct announcement API endpoint and add optional content fields (#20)

## Summary

- Fixes the announcement API URL from `/announcement` to `/api/announcement`
- Adds three optional additional content text inputs (Parts 2–4) to the announcement modal
- The bot concatenates all non-empty content fields with double newlines before forwarding to the API
- Only the first content field and the category selector remain required

## Test Plan

- [ ] Run `/announcement` and verify the modal opens with four content fields and a category selector
- [ ] Submit with only the first content field filled — verify it sends correctly
- [ ] Submit with multiple content fields filled — verify they are concatenated in the API request
- [ ] Verify the API no longer returns HTTP 405

Reviewed-on: #20
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

bot/src/config/entitlements.ts

@@ -3,12 +3,12 @@
  * @license Naomi's Public License
  * @author Naomi Carrigan
  */
+const naomiId = "465650873650118659";
+
 const entitledGuilds = [
   "1354624415861833870",
 ];
 
-const entitledUsers = [
-  "465650873650118659",
-];
+const entitledUsers = [ naomiId ];
 
-export { entitledGuilds, entitledUsers };
+export { entitledGuilds, entitledUsers, naomiId };