go to settings linking implemented

src/commands.ts

@@ -10,11 +10,13 @@ export namespace ModestCommands {
         let executable: string | undefined =
             vscode.workspace.getConfiguration("modest").get("executableLocation");
 
-        if (executable === undefined) {
+        if (executable === undefined || executable === "") {
             vscode.window.showInformationMessage(
                 "It looks like you don't have the modest configurable located yet.", "Go to settings")
                 .then(result => {
-                    //TODO: Figure out how to link to settings.
+                    if (result !== undefined) {
+                        vscode.commands.executeCommand("workbench.action.openSettings", "modest.executableLocation");
+                    }
                 });
             return;
         }