Reorganize directories (#3462)

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

docs/examples/to_bson.cpp

@@ -0,0 +1,21 @@
+#include <iostream>
+#include <iomanip>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // create a JSON value
+    json j = R"({"compact": true, "schema": 0})"_json;
+
+    // serialize it to BSON
+    std::vector<std::uint8_t> v = json::to_bson(j);
+
+    // print the vector content
+    for (auto& byte : v)
+    {
+        std::cout << "0x" << std::hex << std::setw(2) << std::setfill('0') << (int)byte << " ";
+    }
+    std::cout << std::endl;
+}