Make types encoding more future-proof by adding type annotations
There're no type annotations specified as of now, however we are keeping
the door open for ourselves to add them later.
#
# array: <type=6> <uuid> <pos>
#
+# type_anno <type=f0..ff> <uuid> <str>
+# -- A type annotation; 0xf0 <= <type> <= 0xff.
+# Drivers should ignore unknown type annotations.
+#
+#
# where:
#
# <pos> 2 bytes (uint16) position of the type in the description
