Add polyfill for promise.allsettled

.Rbuildignore

@@ -3,6 +3,8 @@
 ^\.Rproj\.user$
 ^\.travis\.yml$
 ^\.BBSoptions$
+^\.envrc$
+^\.nvmrc$
 ^.github$
 ^package\.json$
 ^package-lock\.json$

.envrc

@@ -0,0 +1 @@
+use nvm

.nvmrc

@@ -0,0 +1 @@
+v16.14.2

inst/htmlwidgets/lib/index.js

@@ -1,9 +1,18 @@
 import React from 'react';
 import ReactDOM from 'react-dom';
 import { Vitessce } from 'vitessce';
+import allSettled from 'promise.allsettled';
 import 'vitessce/dist/es/production/static/css/index.css';
 import './index.css';
 
+if((new URLSearchParams(window.location.search)).get("viewer_pane") === "1") {
+    // This Vitessce instance is currently running in the Viewer pane of RStudio.
+    // The built-in browser does not support all modern JavaScript features used by Vitessce.
+    // Click the 'Show in new window' button to run in a standalone web browser if the polyfill does not work.
+    console.log("Detected running in the RStudio Viewer pane which does not implement Promise.allSettled. Using polyfill.");
+    allSettled.shim();
+}
+
 export function render_vitessce(el, config, width, height, theme) {
     ReactDOM.render(
         <Vitessce