[examples] Clean up examples (#8674)

Move various "examples" into snippets. Several examples that were less
than a full mechanism or robot were moved to snippets. `arcadedrive` and
`tankdrive` were removed in favor of their Gamepad variants. `hidrumble`
was removed due to being too simple. `potentiometerpid` was removed
because of low utility. `gyromecanum` replaced `mecanumdrive` for
deduplication and because very few teams run holonomic drivetrains
without gyros.

wpilibcExamples/src/main/cpp/snippets/I2CCommunication/cpp/Robot.cpp

@@ -0,0 +1,48 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include "Robot.hpp"
+
+#include <string>
+
+#include <fmt/format.h>
+
+#include "wpi/driverstation/DriverStation.hpp"
+#include "wpi/system/Timer.hpp"
+
+void Robot::RobotPeriodic() {
+  // Creates a string to hold current robot state information, including
+  // alliance, enabled state, operation mode, and match time. The message
+  // is sent in format "AEM###" where A is the alliance color, (R)ed or
+  // (B)lue, E is the enabled state, (E)nabled or (D)isabled, M is the
+  // operation mode, (A)utonomous or (T)eleop, and ### is the zero-padded
+  // time remaining in the match.
+  //
+  // For example, "RET043" would indicate that the robot is on the red
+  // alliance, enabled in teleop mode, with 43 seconds left in the match.
+
+  std::string allianceString = "U";
+  auto alliance = wpi::DriverStation::GetAlliance();
+  if (alliance.has_value()) {
+    if (alliance == wpi::DriverStation::Alliance::kRed) {
+      allianceString = "R";
+    } else {
+      allianceString = "B";
+    }
+  }
+
+  auto string =
+      fmt::format("{}{}{}{:03}", allianceString,
+                  wpi::DriverStation::IsEnabled() ? "E" : "D",
+                  wpi::DriverStation::IsAutonomous() ? "A" : "T",
+                  static_cast<int>(wpi::Timer::GetMatchTime().value()));
+
+  arduino.WriteBulk(reinterpret_cast<uint8_t*>(string.data()), string.size());
+}
+
+#ifndef RUNNING_WPILIB_TESTS
+int main() {
+  return wpi::StartRobot<Robot>();
+}
+#endif

wpilibcExamples/src/main/cpp/snippets/I2CCommunication/include/Robot.hpp

@@ -0,0 +1,25 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#pragma once
+
+#include <array>
+
+#include "wpi/framework/TimedRobot.hpp"
+#include "wpi/hardware/bus/I2C.hpp"
+
+/**
+ * This is a sample program demonstrating how to communicate to a light
+ * controller from the robot code using the roboRIO's I2C port.
+ */
+class Robot : public wpi::TimedRobot {
+ public:
+  void RobotPeriodic() override;
+
+  static constexpr wpi::I2C::Port kPort = wpi::I2C::Port::kPort0;
+
+ private:
+  static constexpr int deviceAddress = 4;
+  wpi::I2C arduino{kPort, deviceAddress};
+};