Added Stadia icon (#1301)

* Added Stadia icon

* Fixed the mixup of the Stadia source in the json file and linked the page instead of the exact icon

* Added "icon" prefix to the Stadia icon

_data/simple-icons.json

@@ -2330,6 +2330,11 @@
             "hex": "0690FA",
             "source": "https://stackshare.io/branding"
         },
+        {
+            "title": "Stadia",
+            "hex": "CD2640",
+            "source": "https://stadia.dev"
+        },
         {
             "title": "Statamic",
             "hex": "1F3641",

icons/stadia.svg

@@ -0,0 +1 @@
+<svg role="img" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>Stadia icon</title><path d="M.202 8.668a.482.482 0 0 0-.202.39v.006c0 .064.014.128.04.19l2.298 5.204c.102.23.364.343.602.259 1.504-.536 6.713-2.233 10.083-1.318 0 0-3.381.196-6.438 2.593a.48.48 0 0 0-.142.571l1.029 2.326.396.929c.094.22.395.247.528.047.713-1.074 1.916-1.611 3.072-2.08a17.647 17.647 0 0 1 3.679-1.05 15.993 15.993 0 0 1 4.07-.167.481.481 0 0 0 .503-.335l1.038-3.317a.48.48 0 0 0-.176-.531c-1.158-.838-5.741-3.654-13.802-2.523 0 0 6.878-3.951 15.61.39a.481.481 0 0 0 .673-.288l.915-2.925A.484.484 0 0 0 24 6.902v-.014a.48.48 0 0 0-.243-.41C22.66 5.858 18.95 4 13.846 4 9.934 4 5.203 5.09.202 8.668"/></svg>