fix docs

skiplist/README.md

@@ -52,48 +52,3 @@ func main() {
 	}
 }
 ```
-
-## Using SkipListMap (pre-generics Go <1.18)
-
-Here's an example on how to use it with versions lower than Go 1.18:
-
-```go
-skipListMap := skiplist.NewSkipListMap(skiplist.IntComparator)
-skipListMap.Insert(13, 91)
-skipListMap.Insert(3, 1)
-skipListMap.Insert(5, 2)
-log.Printf("size: %d", skipListMap.Size())
-
-it, _ := skipListMap.Iterator()
-for {
-    k, v, err := it.Next()
-    if err == skiplist.Done {
-        break
-    }
-    log.Printf("key: %d, value: %d", k, v)
-}
-
-log.Printf("starting at key: %d", 5)
-it, _ = skipListMap.IteratorStartingAt(5)
-for {
-    k, v, err := it.Next()
-    if err == skiplist.Done {
-        break
-    }
-    log.Printf("key: %d, value: %d", k, v)
-}
-
-log.Printf("between: %d and %d", 8, 50)
-it, _ = skipListMap.IteratorBetween(8, 50)
-for {
-    k, v, err := it.Next()
-    if err == skiplist.Done {
-        break
-    }
-    log.Printf("key: %d, value: %d", k, v)
-}
-
-```
-
-You can supply any kind of element and comparator to sort arbitrary structs and primitives.
-