docs: add some docs

I made this a while back, it is very incomplete, just adding in case anyone's looking for the opcodes

docs/device-info.md

@@ -0,0 +1,26 @@
+---
+opcode: 0x001D
+title: Device Information
+description: Information about AirPods, such as model, firmware version, and serial number. This can not be requested from the accessory; it is only sent by the accessory to the host upon connection.
+---
+
+## Device information
+
+The device information packet is sent by the accessory to the host upon connection. It contains various details about the AirPods, including model number, software version, and serial number.
+
+Each `null` indicates the start of a new string field.
+
+The data is in this order:
+- Name
+- Model number
+- Manufacturer (always "Apple Inc.")
+- Serial number
+- Version 1
+- Version 2
+- Hardware revision (?) (I have `1.0.0`)
+- Updater app version (?) (I have `com.apple.accessory.updater.app.71`)
+- Serial number (Left Bud)
+- Serial number (Right Bud)
+- Version (?) (I have `8454371`)
+- A few more bytes, I don't know what they are
+