Update release notes/v0.31.0.md

Co-authored-by: na-- <[email protected]>

release notes/v0.31.0.md

@@ -10,7 +10,7 @@ In addition to this, it is now possible to implement custom k6 output extensions
 
 Writing output extensions is done very similarly to [how JS module extensions are currently written](https://k6.io/blog/extending-k6-with-xk6), though instead of calling `js/modules.Register()`, you should implement the new [`Output` interface](https://github.com/loadimpact/k6/blob/2036baeaa83d76ce17aae95fef7e78e3ef24c735/output/types.go#L51-L74) and call [`output.RegisterExtension()`](https://github.com/loadimpact/k6/blob/2036baeaa83d76ce17aae95fef7e78e3ef24c735/output/extensions.go#L47) with your constructor.
 
-We are working on the proper documentation for this, as well as the overdue xk6 documentation about JS extensions, so keep a lookout for those on https://k6.io/docs/ .
+We are working on the proper documentation for this, as well as the overdue xk6 documentation about JS extensions, so keep a lookout for those on [k6.io/docs](https://k6.io/docs/).
 
 
 ### Marking requests as failed ([#1856](https://github.com/loadimpact/k6/pull/1856))