Can be replaced with `#!cpp app.route<crow::black_magick::get_parameter_tag(url)>(url)` or `#!cpp app.route_dynamic(url)` if you're using VS2013 or want runtime URL evaluation. Although this usage is **NOT** recommended.
Using `/hello` means the client will need to access `http://example.com/hello` in order to access the route.<br>
A path can have parameters, for example `/hello/<int>` will allow a client to input an int into the url which will be in the handler (something like `http://example.com/hello/42`).<br>
Parameters can be `<int>`, `<uint>`, `<double>`, `<string>`, or `<path>`.<br>
you can see the first `<int>` is defined as `a` and the second as `b`. If you were to run this and call `http://example.com/add/1/2`, the result would be a page with `3`. Exciting!
You can change the HTTP methods the route uses from just the default `GET` by using `method()`, your route macro should look like `CROW_ROUTE(app, "/add/<int>/<int>").methods(crow::HTTPMethod::GET, crow::HTTPMethod::PATCH)` or `CROW_ROUTE(app, "/add/<int>/<int>").methods("GET"_method, "PATCH"_method)`.
Basically a piece of code that gets executed whenever the client calls the associated route, usually in the form of a [lambda expression](https://en.cppreference.com/w/cpp/language/lambda). It can be as simple as `#!cpp ([](){return "Hello World"})`.<br><br>
You can also access the URL parameters in the handler using `#!cpp req.url_params.get("param_name");`. If the parameter doesn't exist, `nullptr` is returned.<br><br>
parameters inside the body can be parsed using `#!cpp req.get_body_params();`. which is useful for requests of type `application/x-www-form-urlencoded`. Its format is similar to `url_params`.
If you have your own class you want to return (without converting it to string and returning that), you can use the `crow::returnable` class.<br>
to use the returnable class, you only need your class to publicly extend `crow::returnable`, add a `dump()` method that returns your class as an `std::string`, and add a constructor that has a `Content-Type` header as a string argument.<br><br>
Instead of assigning a response code, you can use the `crow::status` enum, for example you can replace `crow::response(200)` with `crow::response(crow::status::OK)`
By default, any request that Crow can't find a route for will return a simple 404 response. You can change that to return a default route using the `CROW_CATCHALL_ROUTE(app)` macro. Defining it is identical to a normal route, even when it comes to the `const crow::request&` and `crow::response&` parameters being optional.
