Add tasks for all the new languages

Task/Doubly-linked-list-Element-insertion/Axe/doubly-linked-list-element-insertion.axe

@@ -0,0 +1,7 @@
+Lbl INSERT
+{r₁+2}ʳ→{r₂+2}ʳ
+r₁→{r₂+4}ʳ
+r₂→{{r₂+2}ʳ+4}ʳ
+r₂→{r₁+2}ʳ
+r₁
+Return

Task/Doubly-linked-list-Element-insertion/Nim/doubly-linked-list-element-insertion.nim

@@ -0,0 +1,6 @@
+proc insertAfter[T](l: var List[T], r, n: Node[T]) =
+  n.prev = r
+  n.next = r.next
+  n.next.prev = n
+  r.next = n
+  if r == l.tail: l.tail = n

Task/Doubly-linked-list-Element-insertion/Oforth/doubly-linked-list-element-insertion.oforth

@@ -0,0 +1,7 @@
+: test      // ( -- aDList )
+| dl |
+   DList new ->dl
+   dl insertFront("A")
+   dl insertBack("B")
+   dl head insertAfter(DNode new("C", null , null))
+   dl ;