[examples] Adding XRP java and cpp examples for Timed Robot (#8599)

Adding an example (one C++ and one Java) for using TimedRobot with the
XRP.

wpilibcExamples/src/main/cpp/examples/examples.json

@@ -609,6 +609,22 @@
       "xrp"
     ]
   },
+  {
+    "name": "XRP Timed",
+    "description": "An very basic timed robot program that can be used with the XRP reference robot design.",
+    "tags": [
+      "XRP",
+      "Differential Drive",
+      "XboxController"
+    ],
+    "foldername": "Xrptimed",
+    "gradlebase": "cppxrp",
+    "mainclass": "Main",
+    "commandversion": 2,
+    "extravendordeps": [
+      "xrp"
+    ]
+  },
   {
     "name": "StateSpaceFlywheel",
     "description": "Control a flywheel using a state-space model (based on values from CAD), with a Kalman Filter and LQR.",