fix: RegExp.Result.t should be an array of options

Author: illusionalsagacity

src/Core__RegExp.res

@@ -1,7 +1,7 @@
 type t = Js.Re.t
 
 module Result = {
-  type t = array<string>
+  type t = array<option<string>>
   @get_index external fullMatch: (t, @as(0) _) => string = ""
   @send external matches: (t, @as(1) _) => array<string> = "slice"
   @get external index: t => int = "index"

src/Core__RegExp.resi

@@ -13,7 +13,7 @@ module Result: {
   /**
   Type representing the result of a `RegExp` execution.
   */
-  type t = array<string>
+  type t = array<option<string>>
 
   /**
   `fullMatch(regExpResult)` returns the full string that matched in this result.