fix: no idea (#1200)

Author: kellyjosephprice

__tests__/browser/__image_snapshots__/markdown-test-js-visual-regression-tests-rdmd-syntax-renders-callout-tests-without-surprises-2-snap.png

@@ -5,6 +5,12 @@ const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));
 
 describe('visual regression tests', () => {
   describe('rdmd syntax', () => {
+    beforeAll(async () => {
+      // try warming up the browser???
+      const uri = 'http://localhost:9966/#/callouts?ci=true&darkModeDataAttribute=true';
+      await page.goto(uri, { waitUntil: 'networkidle0' });
+    });
+
     beforeEach(async () => {
       // The ToC disappears somewhere below 1200, 1175-ish?
       await page.setViewport({ width: 1400, height: 800 });