Add tasks for all the new languages

Task/Collections/Sidef/collections-1.sidef

@@ -0,0 +1,5 @@
+# creating an empty array and adding values
+var a = []          #=> []
+a[0] = 1            #=> [1]
+a[3] = "abc"        #=> [1, nil, nil, "abc"]
+a << 3.14           #=> [1, nil, nil, "abc", 3.14]