Add PlatformIO project setup, local libraries, and PCB Gerber files

- Add platformio.ini for ESP32 DevKit (Arduino framework, espressif32 6.10.0)
- Vendor ArduinoJson, MPU6050_tockn, SCServo, Simple_FOC, and WebSockets
  so a fresh clone builds without downloading dependencies
- Add .gitignore rules for PlatformIO/IDE build artifacts
- Add controller PCB Gerber and drill files

3.Software/libraries/ArduinoJson/extras/tests/JsonArray/std_string.cpp

@@ -0,0 +1,32 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright © 2014-2023, Benoit BLANCHON
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+static void eraseString(std::string& str) {
+  char* p = const_cast<char*>(str.c_str());
+  while (*p)
+    *p++ = '*';
+}
+
+TEST_CASE("std::string") {
+  DynamicJsonDocument doc(4096);
+  JsonArray array = doc.to<JsonArray>();
+
+  SECTION("add()") {
+    std::string value("hello");
+    array.add(value);
+    eraseString(value);
+    REQUIRE(std::string("hello") == array[0]);
+  }
+
+  SECTION("operator[]") {
+    std::string value("world");
+    array.add("hello");
+    array[0] = value;
+    eraseString(value);
+    REQUIRE(std::string("world") == array[0]);
+  }
+}