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/JsonSerializer/std_string.cpp

@@ -0,0 +1,57 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright © 2014-2023, Benoit BLANCHON
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("serialize JsonArray to std::string") {
+  DynamicJsonDocument doc(4096);
+  JsonArray array = doc.to<JsonArray>();
+  array.add(4);
+  array.add(2);
+
+  SECTION("serializeJson()") {
+    std::string json;
+    serializeJson(array, json);
+
+    REQUIRE("[4,2]" == json);
+  }
+
+  SECTION("serializeJsonPretty") {
+    std::string json;
+    serializeJsonPretty(array, json);
+
+    REQUIRE("[\r\n  4,\r\n  2\r\n]" == json);
+  }
+}
+
+TEST_CASE("serialize JsonObject to std::string") {
+  DynamicJsonDocument doc(4096);
+  JsonObject obj = doc.to<JsonObject>();
+  obj["key"] = "value";
+
+  SECTION("object") {
+    std::string json;
+    serializeJson(doc, json);
+
+    REQUIRE("{\"key\":\"value\"}" == json);
+  }
+
+  SECTION("serializeJsonPretty") {
+    std::string json;
+    serializeJsonPretty(doc, json);
+
+    REQUIRE("{\r\n  \"key\": \"value\"\r\n}" == json);
+  }
+}
+
+TEST_CASE("serialize an std::string containing a NUL") {
+  StaticJsonDocument<256> doc;
+  doc.set(std::string("hello\0world", 11));
+  CHECK(doc.memoryUsage() == 12);
+
+  std::string json;
+  serializeJson(doc, json);
+  CHECK("\"hello\\u0000world\"" == json);
+}