feat(package.json): add information urls to package

The changelog, documentation and license url has been added to the
package.json as these are used within the Unity package manager.

Author: thestonefox

package.json

@@ -2,6 +2,9 @@
     "name": "io.extendreality.tilia.input.unityinputsystem",
     "displayName": "Tilia Input UnityInputSystem",
     "description": "Input wrappers for the Unity Input System and a collection of common input prefabs.",
+    "changelogUrl": "https://github.com/ExtendRealityLtd/Tilia.Input.UnityInputSystem/blob/master/CHANGELOG.md",
+    "documentationUrl": "https://github.com/ExtendRealityLtd/Tilia.Input.UnityInputSystem/tree/master/Documentation",
+    "licensesUrl": "https://github.com/ExtendRealityLtd/Tilia.Input.UnityInputSystem/blob/master/LICENSE.md",
     "version": "1.1.19",
     "unity": "2019.1",
     "unityRelease": "0f1",