Meta: Add JSON parsing library dependency

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "vendor/json"]
+	path = vendor/json
+	url = https://github.com/nlohmann/json

CMakeLists.txt

@@ -56,6 +56,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 include_directories(
 	"src"
 	"test"
+	"vendor/json/include"
 )
 
 # Define source files

vendor/json

@@ -0,0 +1 @@
+Subproject commit eec79d4e8a306d0dc389d6ab7294478249069e51