feat(bluetooth): Proper bond management, identity support for non-splits

* Add `bt` behavior that can be used to perform certain actions,
  such as next/prev identity, reset identity, etc.
  NOTE: Multiple identities is only supported for non-split shields,
  due to missing Zephyr identity functionality for dual
  central/peripheral devices.
* Proper bond reset tied to action, that honors peripheral bonds,
  so folks can reset and pair to other hosts, without breaking
  bonds between splt halves.

docs/docs/behavior/bluetooth.md

@@ -0,0 +1,82 @@
+---
+title: Bluetooth Behavior
+sidebar_label: Bluetooth
+---
+
+## Summary
+
+The bluetooth behavior allows management of various settings and states related to the bluetooth connection(s)
+between the keyboard and the host.
+
+## Bluetooth Command Defines
+
+Bluetooth command defines are provided through the [`dt-bindings/zmk/bt.h`](https://github.com/zmkfirmware/zmk/blob/main/app/include/dt-bindings/zmk/bt.h) header,
+which is added at the top of the keymap file:
+
+```
+#include <dt-bindings/zmk/bt.h>
+```
+
+This will allow you to reference the actions defined in this header such as `BT_IDENT_CLR_CMD`.
+
+Here is a table describing the command for each define:
+
+| Define              | Action                                                |
+| ------------------- | ----------------------------------------------------- |
+| `BT_IDENT_CLR_CMD`  | Clear paired keyboards (for the current identity)[^1] |
+| `BT_IDENT_NEXT_CMD` | Switch to the next identity[^1]                       |
+| `BT_IDENT_PREV_CMD` | Switch to the previous identity                       |
+| `BT_IDENT_SEL_CMD`  | Switch to a specific numbered identity                |
+| `BT_RST_CMD`        | Hard reset of all bluetooth bonds                     |
+
+Because the `BT_IDENT_SEL_CMD` command takes an additional parameter, the numeric index of the identity to select, _all_ the commands for the bluetooth behavior must take that additional parameter, and ignore the value. To make this easier,
+there are alias defines that add those default parameters for you:
+
+| Define          | Action                                                                                  |
+| --------------- | --------------------------------------------------------------------------------------- |
+| `BT_IDENT_CLR`  | Alias for `BT_IDENT_CLR_CMD 0` to clear paired keyboards (for the current identity)[^1] |
+| `BT_IDENT_NEXT` | Alias for `BT_IDENT_NEXT_CMD 0` to switch to the next identity[^1]                      |
+| `BT_IDENT_PREV` | Alias for `BT_IDENT_PREV_CMD 0` to switch to the previous identity                      |
+| `BT_IDENT_SEL`  | Alias for `BT_IDENT_SEL_CMD` to switch to a specific numbered identity                  |
+| `BT_RST`        | Alias for `BT_RST_CMD 0` to reset all bonds[^2]                                         |
+
+[^1]: Multiple keyboard identities/profiles is only support on non-split keyboards as of this time.
+[^2]: This may interrupt pairing between both halves of a split keyboard. For split keyboards, it is preferred to use the [/docs/bond-reset] combo to clear bonds on both devices
+
+## Bluetooth Behavior
+
+The bluetooth behavior completes an bluetooth action given on press.
+
+### Behavior Binding
+
+- Reference: `&bt`
+- Parameter #1: The bluetooth command define, e.g. `BT_IDENT_CLR_CMD` or `BT_RST_CMD`
+- Parameter #2: The parameter for the command, when used to identify an identity/profile to select, e.g. `0`
+
+### Examples
+
+1. Behavior to clear the paired host:
+
+   ```
+   &bt BT_IDENT_CLR
+   ```
+
+1. Behavior to hard reset all bonded devices[^2]:
+
+   ```
+   &bt BT_IDENT_CLR
+   ```
+
+Examples for non-split keyboards with multiple identities:
+
+1. Behavior to switch to the next identity:
+
+   ```
+   &bt BT_IDENT_NEXT
+   ```
+
+1. Behavior to switch to the specific numbered identity:
+
+   ```
+   &bt BT_IDENT_SEL 1
+   ```