add firefox extension template

externs/webextension_polyfill/urlbar/Static.hx

@@ -0,0 +1,48 @@
+package webextension_polyfill.urlbar;
+
+typedef Static = {
+	/**
+		Closes the urlbar view in the current window.
+	**/
+	function closeView():Void;
+	/**
+		Focuses the urlbar in the current window.
+	**/
+	function focus(?select:Bool):Void;
+	/**
+		Starts a search in the urlbar in the current window.
+	**/
+	function search(searchString:String, ?options:SearchOptions):Void;
+	/**
+		Before a query starts, this event is fired for the given provider. Its purpose is to request the provider's behavior for
+		the query. The listener should return a behavior in response. By default, providers are inactive,
+		so if your provider should always be inactive, you don't need to listen for this event.
+	**/
+	var onBehaviorRequested : OnBehaviorRequestedEvent;
+	/**
+		This event is fired when the user starts and ends an engagement with the urlbar.
+	**/
+	var onEngagement : OnEngagementEvent;
+	/**
+		This event is fired for the given provider when a query is canceled. The listener should stop any ongoing fetch or
+		creation of results and clean up its resources.
+	**/
+	var onQueryCanceled : OnQueryCanceledEvent;
+	/**
+		When a query starts, this event is fired for the given provider if the provider is active for the query and there are no
+		other providers that are restricting. Its purpose is to request the provider's results for the query.
+		The listener should return a list of results in response.
+	**/
+	var onResultsRequested : OnResultsRequestedEvent;
+	/**
+		Typically, a provider includes a <code>url</code> property in its results' payloads.
+		When the user picks a result with a URL, Firefox automatically loads the URL. URLs don't make sense for every result
+		type, however. When the user picks a result without a URL, this event is fired. The provider should take an appropriate
+		action in response. Currently the only applicable <code>ResultTypes</code> are <code>dynamic</code> and <code>tip</code>.
+	**/
+	var onResultPicked : OnResultPickedEvent;
+	/**
+		Enables or disables the engagement telemetry.
+	**/
+	var engagementTelemetry : webextension_polyfill.types.Setting;
+};