remove reasonml.org links in favor of melange

Author: davesnx

docs/simple.md

@@ -74,7 +74,7 @@ let make = () => {
 
 ### A Component that Renders a List of Items
 
-This component uses [Belt](https://reasonml.org/apis/javascript/latest/belt), Reason's preferred Standard Library.
+This component uses [Belt][melange-belt], from [melange][melange-home].
 
 ```reason
 /* We define the type of the item (this is a record) */
@@ -96,3 +96,6 @@ let make = (~items) =>
     }
   </ul>;
 ```
+
+[melange-belt]: https://melange.re/v4.0.0/api/re/melange/Belt
+[melange-home]: https://melange.re/v4.0.0/

docs/working-with-optional-data.md

@@ -32,7 +32,7 @@ let label = selected->Belt.Option.mapWithDefault(
 
 What this is doing: "if selected exists, go look into `selected##name` otherwise return `Select a Color`".
 
-Read more about [`mapWithDefault`](https://reasonml.org/apis/javascript/latest/belt/option) here.
+Read more about [`mapWithDefault`][melange-belt-option-map-with-default] here.
 
 ### Something or Nothing
 
@@ -78,3 +78,4 @@ Read more about [`getWithDefault`][melange-belt-option-get-with-default] here.
 
 [melange-belt]: https://melange.re/v4.0.0/api/re/melange/Belt
 [melange-belt-option-get-with-default]: https://melange.re/v4.0.0/api/re/melange/Belt/Option/index.html#val-getWithDefault
+[melange-belt-option-map-with-default]: https://melange.re/v4.0.0/api/re/melange/Belt/Option/index.html#val-mapWithDefault