Added Unity (#1361)

_data/simple-icons.json

@@ -2665,6 +2665,11 @@
             "hex": "00BEC1",
             "source": "https://umbraco.com/"
         },
+        {
+            "title": "Unity",
+            "hex": "000000",
+            "source": "https://unity.com/"
+        },
         {
             "title": "Unsplash",
             "hex": "000000",

icons/unity.svg

@@ -0,0 +1 @@
+<svg role="img" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>Unity icon</title><path d="M19.9 19.2L15.6 12l4.3-7.2L22 12l-2.1 7.2zm-9.5-.7L5 13.2h8.6l4.3 7.2-7.5-1.9zm0-13.1l7.5-1.9-4.3 7.2H4.9c0 .1 5.5-5.3 5.5-5.3zm11-5.4l-9.8 2.5L10.1 5H7.2L0 12l7.2 7h2.9l1.4 2.5 9.8 2.5 2.6-9.5-1.4-2.5L24 9.5 21.4 0z"/></svg>