README: specify weblink v1 requires a Haxe nightly version now

PXshadow · PXshadow · commit 5b0e43c6c941 · 2025-10-31T16:00:35.000-07:00
diff --git a/README.md b/README.md
@@ -39,6 +39,7 @@ Include in build.hxml
 ```
 
 # Targets
+* requires nightly [haxe version](https://haxe.org/download/nightlies/)
 * requires libuv
 * hashlink (uses libuv)
 
