add yaml serialization support (#3)

this change adds serialization of payloads as YAML, but not parsing. The implementation is somewhat based on the JSON path, and may be collapsed eventually as it is possible to serialize JSON format using the same code

it also separates out the JSON serialization into a separate file for ease of maintenance

any HTTP request response may be formatted as yaml by using a `.yaml` suffix or an `Accept: text/yaml` header

1 files changed, 2 insertions, 0 deletions

diff --git a/xmake.lua b/xmake.lua
index 83d85a6d9..02781541b 100644
--- a/xmake.lua
+++ b/xmake.lua
@@ -15,6 +15,8 @@ add_requires(
     "vcpkg::json11",
     "vcpkg::lua",
     "vcpkg::lz4",
+    "vcpkg::ryml",
+    "vcpkg::c4core",
     "vcpkg::robin-map",
     "vcpkg::sol2",
     "vcpkg::spdlog",