added documentation for line-stroke

docs/participants.typ

@@ -34,6 +34,7 @@
 /// - invisible (bool): If set to true, the participant will not be shown
 /// - shape (str): The shape of the participant. Possible values in @@SHAPES
 /// - color (color): The participant's color
+/// - line-stroke (stroke): The participant's line style (defaults to a light gray dashed line)
 /// - custom-image (none, image): If shape is 'custom', sets the custom image to display
 /// - show-bottom (bool): Whether to display the bottom shape
 /// - show-top (bool): Whether to display the top shape
@@ -45,6 +46,11 @@
   invisible: false,
   shape: "participant",
   color: rgb("#E2E2F0"),
+  line-stroke: (
+    dash: "dashed",
+    paint: gray.darken(40%),
+    thickness: .5pt
+  ),
   custom-image: none,
   show-bottom: true,
   show-top: true,