Motorbike signals as additional layer

As discussed previously, mixing different kinds vehicles
in one vspec structure might lead to too generic structures
and confusion. One way to achieve such variety is through profiles
as overlayes. This is a first proposal on how it could look like,
open for discussion.

Signed-off-by: Daniel Wilms <Daniel.DW.Wilms@bmw.de>

overlays/profiles/motorbike.vspec

@@ -0,0 +1,45 @@
+#
+# (C) 2022, Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
+#
+# All files and artifacts in this repository are licensed under the
+# provisions of the license provided by the LICENSE file in this repository.
+#
+#
+# This file contains adoptions to the main spec concering motorbikes.
+# It mainly addresses istantiation issues (e.g. wheels) and 
+# additional signals, which are motorbike specific (e.g. handlebars).
+# 
+# Currently this file serves as a very early draft, which serves 
+# more as an example of overlays and is not considered a part of the
+# official specification.
+
+
+# Branches used for the structure, not adopted in any way
+Vehicle:
+    type: branch
+
+Vehicle.Chassis:
+    type: branch
+
+Vehicle.Chassis.Axle:
+    type: branch
+
+# Changed instantiation
+Vehicle.Chassis.Axle.Wheel:
+    type: branch
+    instances: ["Center"]
+
+# Branches used for the structure, not adopted in any way
+Vehicle.Cabin:
+    type: branch
+
+# Additional cabin information
+Vehicle.Cabin.Handlebar:
+  type: branch
+  description: Branch for the handlebar of a motorbike.
+
+Vehicle.Cabin.Handlebar.GripHeating:
+  type: sensor
+  datatype: string
+  allowed: ["HEATING_OFF", "HEATING_STEP_1", "HEATING_STEP_2", "HEATING_STEP_3", "HEATING_STEP_4", "HEATING_STEP_5", "HEATING_AUTOMATIC"]
+  description: Grip Heating Status in motorbikes. The signal shows if the handlebar grip heating is on or not, and if yes, to which level.