Add deadman switch cog

README.md

@@ -8,6 +8,9 @@ Homepage: https://homepage.kingstons-scrapyard.net/
 
 ## Table of Contents
 
+**Deadman**
+- [Deadman](#deadman)
+
 **AutoRoom**
 - [Installation](#installation)
 - [AutoRoom](#autoroom)
@@ -49,6 +52,35 @@ Homepage: https://homepage.kingstons-scrapyard.net/
 [p]load autoroom
 ```
 
+Deadman (bot owner only):
+
+```
+[p]cog install scrapyard deadman
+[p]load deadman
+```
+
+---
+
+## Deadman
+
+A member of the Scrapyard Cogworks package. A deadman switch that alerts listed users if not disabled before it expires.
+
+- **Owner only**: Only the bot owner can arm, disable, or check status.
+- **Arm**: `[p]deadman arm <duration> @user1 @user2 [channel]`
+- **Disable**: `[p]deadman disable`
+- **Status**: `[p]deadman status`
+
+**Duration format** (flexible string):
+- `30s` = 30 seconds
+- `6h` = 6 hours
+- `2h30m` = 2 hours 30 minutes
+- `1d` = 1 day
+- `1d12h` = 1 day 12 hours
+
+Supported units: `s`, `m`, `h`, `d`, `w` (and their full names).
+
+When the switch is armed, the bot stores the expiry time and alerts users by DM. If an optional channel is provided, it also posts the alert there. If `[p]deadman disable` is not run before expiry, the listed users are DM'd and pinged that "the deadman switch has been TRIGGERED".
+
 ---
 
 ## AutoRoom