docs: minor corrections to dynamic/decode

Author: isaacharrisholt

src/gleam/dynamic/decode.gleam

@@ -232,7 +232,7 @@
 ////   use name <- decode.field("name", decode.string)
 ////   use badge_count <- decode.field("badge-count", decode.int)
 ////   decode.success(Trainer(name, badge_count))
-//// })
+//// }
 ////
 //// let gym_leader_decoder = {
 ////   use name <- decode.field("name", decode.string)
@@ -242,7 +242,7 @@
 //// ```
 ////
 //// A third decoder can be used to extract and decode the `"type"` field, and the
-//// `then` function then returns whichever decoder is suitable for the document.
+//// expression can evaluate to whichever decoder is suitable for the document.
 ////
 //// ```gleam
 //// // Data: