Add unpopulated option to additional components qty multiplier

Co-authored-by: Jeremy Ruhland (hatchery) <jeremy@goopypanther.org>

squash me

docs/syntax.md

@@ -408,6 +408,7 @@ Parts can be added to a connector or cable in the section `<additional-component
                   # when used in a connector:
                   # pincount         number of pins of connector
                   # populated        number of populated positions in a connector
+                  # unpopulated      number of unpopulated positions
                   # when used in a cable:
                   # wirecount        number of wires of cable/bundle
                   # terminations     number of terminations on a cable/bundle

src/wireviz/wv_bom.py

@@ -31,7 +31,7 @@ BomCategory = IntEnum(  # to enforce ordering in BOM
     "BomEntry", "CONNECTOR CABLE WIRE ADDITIONAL_INSIDE ADDITIONAL_OUTSIDE"
 )
 QtyMultiplierConnector = Enum(
-    "QtyMultiplierConnector", "PINCOUNT POPULATED CONNECTIONS"
+    "QtyMultiplierConnector", "PINCOUNT POPULATED UNPOPULATED CONNECTIONS"
 )
 QtyMultiplierCable = Enum(
     "QtyMultiplierCable", "WIRECOUNT TERMINATION LENGTH TOTAL_LENGTH"

src/wireviz/wv_dataclasses.py

@@ -450,6 +450,7 @@ class Connector(TopLevelGraphicalComponent):
         qty_multipliers_computed = {
             "PINCOUNT": self.pincount,
             "POPULATED": num_populated_pins,
+            "UNPOPULATED": self.pincount - num_populated_pins,
             "CONNECTIONS": num_connections,
         }
         for subitem in self.additional_components: