Update readme.md

readme.md

@@ -210,7 +210,7 @@ Lighthouse can produce a report as JSON or HTML.
 
 HTML report:
 
-<p align= "center"><img src="https://raw.githubusercontent.com/GoogleChrome/lighthouse/443ff2c8a297dfd2297dfaca86c4966a87c8574a/assets/example_audit.png" alt="Lighthouse example audit" width="500px"></p>
+<img src="https://raw.githubusercontent.com/GoogleChrome/lighthouse/443ff2c8a297dfd2297dfaca86c4966a87c8574a/assets/example_audit.png" alt="Lighthouse example audit" width="600px">
 
 ### Online Viewer
 
@@ -250,12 +250,12 @@ Useful documentation, examples, and recipes to get you started.
 
 The session from Google I/O 2018 covers the new performance engine, upcoming Lighthouse REST API, and using the Chrome UX report to evaluate real-user data.
 
-<p align= "center">[![Lighthouse @ Google I/O 2018](https://img.youtube.com/vi/UvK9zAsSM8Q/0.jpg)](https://www.youtube.com/watch?v=UvK9zAsSM8Q)</p>
+[![Lighthouse @ Google I/O 2018](https://img.youtube.com/vi/UvK9zAsSM8Q/0.jpg)](https://www.youtube.com/watch?v=UvK9zAsSM8Q)
 
 The session from Google I/O 2017 covers architecture, writing custom audits,
 GitHub/Travis/CI integration, headless Chrome, and more:
 
-<p align= "center">[![Lighthouse @ Google I/O 2017](https://img.youtube.com/vi/NoRYn6gOtVo/0.jpg)](https://www.youtube.com/watch?v=NoRYn6gOtVo)</p>
+[![Lighthouse @ Google I/O 2017](https://img.youtube.com/vi/NoRYn6gOtVo/0.jpg)](https://www.youtube.com/watch?v=NoRYn6gOtVo)
 
 _click to watch the video_