add note about combining ext

htmgo-site/md/docs/7_htmx_extensions/1_overview.md

@@ -16,5 +16,19 @@ h.Html(
 )
 ```
 
+If you need to combine multiple extensions, you can use:
+
+```go
+h.HxExtensions(h.BaseExtensions(), "my-extension"),
+```
+or
+```go
+h.JoinExtensions(
+    h.HxExtension("sse"),
+    h.HxExtension("my-extension"),
+),
+```
+
+
 **Important**: h.BaseExtensions will add the the 'htmgo' extension, which is a required extension for inline scripts to work properly, please always include it in your project.