Add tasks for all the new languages

Task/Metaprogramming/Shen/metaprogramming-1.shen

@@ -0,0 +1,8 @@
+(define make-list
+  [A|D] -> [cons (make-list A) (make-list D)]
+  X -> X)
+
+(defmacro info-macro
+  [info Exp] -> [output "~A: ~A~%" (make-list Exp) Exp])
+
+(info (* 5 6)) \\ outputs [* 5 6]: 30

Task/Metaprogramming/Shen/metaprogramming-2.shen

@@ -0,0 +1,7 @@
+(0-) (defmacro +-macro
+       [A + B] -> [+ A B])
+macro
++-macro
+
+(1-) (1 + (* 2 3))
+7

Task/Metaprogramming/Shen/metaprogramming-3.shen

@@ -0,0 +1,14 @@
+(2-) (tc +)
+true
+
+(3+) (+ 1 2 3)
+6 : number
+
+(4+) +
++ : (number --> (number --> number))
+
+(5-) (tc -)
+false
+
+(6-) (macroexpand [+ 1 2 3])
+[+ 1 [+ 2 3]]