docs: improve JSDoc of PaintParameter and StyleDefault

Document the purpose of some properties in StyleDefault related to activity icons and markers.

src/component/mxgraph/shape/render/icon-painter.ts

@@ -29,10 +29,18 @@ import { BpmnCanvas } from './BpmnCanvas';
  * @experimental
  */
 export interface PaintParameter {
+  /** Underlying 'Canvas' in charge of performing the paint operations. */
   canvas: mxAbstractCanvas2D;
+  /** The dimension and the style of the shape where the icon is painted. */
   shapeConfig: ShapeConfiguration;
+  /** The style configuration of the icon. */
   iconStyleConfig: IconStyleConfiguration;
+  /**
+   * The actual size of the icon will be computed from the shape dimensions using this ratio. The ratio between the original dimensions of the icon are kept.
+   * If not set, use the dimensions defined in the icon implementation.
+   */
   ratioFromParent?: number;
+  /** The called function to set the origin of the icon. Generally, it calls a method of {@link BpmnCanvas}. */
   setIconOriginFunct: (canvas: BpmnCanvas) => void;
 }
 

src/component/mxgraph/style/utils.ts

@@ -33,10 +33,15 @@ import { BpmnStyleIdentifier } from './identifiers';
 export const StyleDefault = {
   STROKE_WIDTH_THIN: 2,
   STROKE_WIDTH_THICK: 5,
+  /** Margin between the bottom of markers and the bottom of the activity. */
   SHAPE_ACTIVITY_BOTTOM_MARGIN: 7,
+  /** Margin between the top of icon and the top of the activity. */
   SHAPE_ACTIVITY_TOP_MARGIN: 7,
+  /** Margin between the left of icon and the left of the activity. */
   SHAPE_ACTIVITY_LEFT_MARGIN: 7,
+  /** Spacing between 2 markers. */
   SHAPE_ACTIVITY_MARKER_ICON_MARGIN: 5,
+  /** Theoretical width of a marker. Used to position the markers when there are several markers. */
   SHAPE_ACTIVITY_MARKER_ICON_SIZE: 20,
   POOL_LABEL_SIZE: 30, // most of BPMN pool are ok when setting it to 30
   POOL_LABEL_FILL_COLOR: 'none',