Add tasks for all the new languages

Task/Equilibrium-index/Sidef/equilibrium-index-1.sidef

@@ -0,0 +1,8 @@
+func eq_index(nums) {
+    var (i, sum, sums) = (0, 0, Hash.new);
+    nums.each { |n|
+        sums{2*sum + n} := [] -> append(i++);
+        sum += n;
+    }
+    sums{sum} \\ [];
+}

Task/Equilibrium-index/Sidef/equilibrium-index-2.sidef

@@ -0,0 +1,10 @@
+var indices = [
+  [-7, 1, 5, 2,-4, 3, 0],
+  [2, 4, 6],
+  [2, 9, 2],
+  [1,-1, 1,-1, 1,-1, 1],
+]
+
+for x in indices {
+    say ("%s => %s" % @|[x, eq_index(x)].map{.dump});
+}