feat: Add Hiring cog for ticket-based applications

Introduces a Discord cog to manage staff and PM hiring through interactive tickets, forms, and buttons. Includes modals for Staff, PM, and HPM applications, as well as commands for posting hiring messages and configuring categories and channels.

hiring/info.json

@@ -0,0 +1,15 @@
+{
+  "author": [ "unstableCogs" ],
+  "install_msg": "Thank you for installing the Hiring cog! Use `[p]help Hiring` for a list of commands.",
+  "name": "Hiring",
+  "short": "A ticket-based system for staff and PM applications.",
+  "description": "Provides /hire and /work commands to manage the staff and PM hiring process through a ticket system with forms and buttons.",
+  "tags": [
+    "hiring",
+    "tickets",
+    "utility",
+    "modmail"
+  ],
+  "requirements": [],
+  "end_user_data_statement": "This cog stores user IDs and the content of their applications for the duration of the hiring process."
+}