Merge pull request #3211 from stacks-network/as-max-len

docs: fix output type of `as-max-len?`

clarity/src/vm/docs/mod.rs

@@ -560,7 +560,7 @@ and outputs a list of the same type with max_len += 1.",
 
 const ASSERTS_MAX_LEN_API: SpecialAPI = SpecialAPI {
     input_type: "sequence_A, uint",
-    output_type: "sequence_A",
+    output_type: "(optional sequence_A)",
     signature: "(as-max-len? sequence max_length)",
     description:
         "The `as-max-len?` function takes a sequence argument and a uint-valued, literal length argument.