Removes Firefox only feature deprecated 3y ago

files/en-us/web/opensearch/index.md

@@ -69,12 +69,6 @@ The XML file that describes a search engine follows the basic template below. Se
 
     For search suggestions, the `application/x-suggestions+json` URL template is used to fetch a suggestion list in [JSON](/en-US/docs/Glossary/JSON) format.
 
-- moz:SearchForm
-
-  - : The URL for the site's search initiation page for the plugin. This lets Firefox users visit the website, and search from the site directly.
-
-    > **Note:** Since this element is Firefox-specific, and not part of the OpenSearch specification, we use the `moz:` XML namespace prefix in the example above to ensure that other user agents that don't support this element can safely ignore it.
-
 ## Autodiscovery of search plugins
 
 Websites with search plugins can advertise them so Firefox users can easily install the plugins.