add json.ml; add test.ml; timestamp jsont

src/dune

@@ -1,8 +1,10 @@
 (executable
  (public_name mte)
  (name mte)
- (modules assets assets_crunch headers mte config util types management)
+ (modules assets assets_crunch headers mte config util management)
  (libraries
+  json
+  types
   headers_lib
   syntax
   ;
@@ -13,6 +15,16 @@
   jsont
   cohttp))
 
+(library
+ (name json)
+ (modules json)
+ (libraries jsont jsont.bytesrw fmt syntax types))
+
+(library
+ (name types)
+ (modules types)
+ (libraries fmt syntax))
+
 (library
  (name headers_lib)
  (modules headers_lib)