Add tasks for all the new languages

Task/Factorial/Wortel/factorial-1.wortel

@@ -0,0 +1 @@
+@fac 10

Task/Factorial/Wortel/factorial-2.wortel

@@ -0,0 +1 @@
+!#~F 10

Task/Factorial/Wortel/factorial-3.wortel

@@ -0,0 +1,3 @@
+!/^* @to 10
+; or
+@prod @to 10

Task/Factorial/Wortel/factorial-4.wortel

@@ -0,0 +1,6 @@
+~!10 &n [
+  @var r 1
+  @for x to n
+    :!*r x
+  r
+]

Task/Factorial/Wortel/factorial-5.wortel

@@ -0,0 +1,14 @@
+@let {
+  fac &{fac n}?{
+    <n 2 n
+    *n !fac -n 1
+  }
+
+  ; memoized
+  facM @mem &n?{
+    <n 2 n
+    *n !facM -n 1
+  }
+
+  [[!fac 10 !facM 10]]
+}