Fix manifest categories reference URL

Author: JoOkuma

template/src/{{module_name}}/napari.yaml.jinja

@@ -2,7 +2,7 @@ name: {{plugin_name}}
 display_name: {{display_name}}
 # use 'hidden' to remove plugin from napari hub search results
 visibility: public
-# see https://napari.org/stable/plugins/manifest.html for valid categories
+# see https://napari.org/stable/plugins/technical_references/manifest.html#fields for valid categories
 categories: ["Annotation", "Segmentation", "Acquisition"]
 contributions:
   commands:{% if include_reader_plugin %}