fix: Missing highestPort property on typescript definition

Signed-off-by: Bruno Gaspar <[email protected]>

Author: brunogaspar

lib/portfinder.d.ts

@@ -33,6 +33,11 @@ interface PortFinderOptions{
  */
 export let basePort: number;
 
+/**
+ * The highest port to end any port search from.
+ */
+export let highestPort: number;
+
 /**
  * Responds with a unbound port on the current machine.
  */