add 'graphics.ssao' setting

src/settings.hpp

@@ -77,6 +77,8 @@ struct GraphicsSettings {
     IntegerSetting chunkMaxRenderers {6, -4, 32};
     /// @brief Advanced render pipeline
     FlagSetting advancedRender {true};
+    /// @brief Screen space ambient occlusion
+    FlagSetting ssao {true};
     /// @brief Shadows quality
     IntegerSetting shadowsQuality {0, 0, 3};
 };