fix(result): correct wrong namespace in Prelude doc comment

The doc comment referenced `Geekeey.Extensions.Result.Prelude` but the actual
namespace is `Geekeey.Request.Result`, so the suggested using directive would
not compile.

CHANGELOG.md

@@ -45,6 +45,10 @@ To have a consistent experience across all packages, some public interfaces have
 
 ### Changed
 
+### Fixed
+
+- **request.result:** Correct the namespace in the `Prelude` doc comment (`Geekeey.Extensions.Result` → `Geekeey.Request.Result`)
+
 ### Removed
 
 [1.0.0]: https://code.geekeey.de/geekeey/request/releases/tag/1.0.0