Overwork documentation (#3444)

* 📝 overwork macro documentation

* 📝 address review comments

* 🔧 add style check to Makefile

* 🙈 overwork .gitignore

* 📌 Pygments 2.12.0 is broken

* ✏️ fix links

* 🚸 adjust output to cppcheck

* 📝 add titles to more admonitions

* ✏️ fix typos

* 📝 document future behavior change

doc/examples/nlohmann_json_serialize_enum_2.cpp

@@ -0,0 +1,33 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+namespace ns
+{
+enum class Color
+{
+    red, green, blue, unknown
+};
+
+NLOHMANN_JSON_SERIALIZE_ENUM(Color,
+{
+    { Color::unknown, "unknown" }, { Color::red, "red" },
+    { Color::green, "green" }, { Color::blue, "blue" },
+    { Color::red, "rot" } // a second conversion for Color::red
+})
+}
+
+int main()
+{
+    // serialization
+    json j_red = ns::Color::red;
+    std::cout << static_cast<int>(ns::Color::red) << " -> " << j_red << std::endl;
+
+    // deserialization
+    json j_rot = "rot";
+    auto rot = j_rot.get<ns::Color>();
+    auto red = j_red.get<ns::Color>();
+    std::cout << j_rot << " -> " << static_cast<int>(rot) << std::endl;
+    std::cout << j_red << " -> " << static_cast<int>(red) << std::endl;
+}