docs: document example shape of PathComponent

Author: nikku

intersect.d.ts

@@ -82,6 +82,12 @@ export function parsePath(path: Path): PathComponent[];
  * ]
  */
 declare type Path = string | PathComponent[];
+/**
+ * A SVG path component, stored as an array with the operation, and parameters
+ * 
+ * @example
+ * ['M', 1, 2]
+ */
 declare type PathComponent = [ string, ...number[] ];
 
 declare interface Intersection {