Reorganize directories (#3462)

* 🚚 move files
* 🚚 rename doc folder to docs
* 🚚 rename test folder to tests

docs/examples/parse__allow_exceptions.cpp

@@ -0,0 +1,36 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // an invalid JSON text
+    std::string text = R"(
+    {
+        "key": "value without closing quotes
+    }
+    )";
+
+    // parse with exceptions
+    try
+    {
+        json j = json::parse(text);
+    }
+    catch (json::parse_error& e)
+    {
+        std::cout << e.what() << std::endl;
+    }
+
+    // parse without exceptions
+    json j = json::parse(text, nullptr, false);
+
+    if (j.is_discarded())
+    {
+        std::cout << "the input is invalid JSON" << std::endl;
+    }
+    else
+    {
+        std::cout << "the input is valid JSON: " << j << std::endl;
+    }
+}