Add tasks for all the new languages

Task/Factorial/EchoLisp/factorial-1.echolisp

@@ -0,0 +1,4 @@
+(define (fact n)
+    (for/product ((f (in-range 2 (1+ n)))) f))
+(fact 10)
+    → 3628800

Task/Factorial/EchoLisp/factorial-2.echolisp

@@ -0,0 +1,6 @@
+(define (fact n)
+    (if (zero? n) 1
+    (* n (fact (1- n)))))
+(remember 'fact)
+(fact 10)
+    → 3628800

Task/Factorial/EchoLisp/factorial-3.echolisp

@@ -0,0 +1,5 @@
+(define (fact n (acc 1))
+(if (zero? n) acc
+    (fact (1- n) (* n acc))))
+(fact 10)
+    → 3628800

Task/Factorial/EchoLisp/factorial-4.echolisp

@@ -0,0 +1,2 @@
+(factorial 10)
+    → 3628800

Task/Factorial/EchoLisp/factorial-5.echolisp

@@ -0,0 +1,4 @@
+(lib 'math)
+math.lib v1.13 ® EchoLisp
+(gamma 11)
+    → 3628800.0000000005