Docs for templated ble_client.write_action (#2225)

components/ble_client.rst

@@ -118,6 +118,20 @@ Example usage:
               characteristic_uuid: 6490FAFE-0734-732C-8705-91B653A081FC
               # List of bytes to write.
               value: [0x01, 0xab, 0xff]
+          - ble_client.ble_write:
+              id: my_ble_client
+              service_uuid: F61E3BE9-2826-A81B-970A-4D4DECFABBAE
+              characteristic_uuid: 6490FAFE-0734-732C-8705-91B653A081FC
+              # A lambda returning an std::vector<uint8_t>.
+              value: !lambda |-
+                  return {0x13, 0x37};
+
+Configuration variables:
+
+- **id** (**Required**, :ref:`config-id`): ID of the associated BLE client.
+- **service_uuid** (**Required**, UUID): UUID of the service to write to.
+- **characteristic_uuid** (**Required**, UUID): UUID of the service's characteristic to write to.
+- **value** (**Required**, Array of bytes or :ref:`lambda <config-lambda>`): The value to be written.
 
 BLE Overview
 ------------