Add battery_last_replaced to event docs

Author: andrew-codechimp

docs/events.md

@@ -24,6 +24,7 @@ You can use this to send notifications in your preferred method.  An example aut
 | `battery_quantity` | `int` | Battery quantity. |
 | `battery_level` | `float` | Battery level % of the device. |
 | `previous_battery_level` | `float` | Previous battery level % of the device. |
+| `battery_last_replaced` | `datetime` | The date the battery was last replaced. |
 | `reminder` | `bool` | Returns true if the event was raised by an action, false if it's from a device event. |  
 
 ### Automation Example
@@ -98,6 +99,7 @@ An example automation below shows how to update the battery_replaced.
 | `battery_quantity` | `int` | Battery quantity. |
 | `battery_level` | `float` | Current battery level % of the device. |
 | `previous_battery_level` | `float` | Previous battery level % of the device. |
+| `battery_last_replaced` | `datetime` | The date the battery was last replaced. |
 
 ### Automation Example
 
@@ -137,6 +139,7 @@ The action can raise multiple events quickly so when using with an automation it
 | `battery_last_reported` | `datetime` | The datetime the battery was last reported. |
 | `battery_last_reported_days` | `int` | The number of days since the battery was last reported. |
 | `battery_last_reported_level` | `float` | The level of the battery when it was last reported. |
+| `battery_last_replaced` | `datetime` | The date the battery was last replaced. |
 
 ### Automation Example