linked demo pages in README render as plaintext in the browser

[iambumblehead]

Description

linked demos in README render as plaintext in the browser

Here's a demo with a more complex bundle.

Here's another demo where you can see a bug: there are two copies of React
in the bundle (perhaps because of out-of-date dependencies).

Steps to reproduce
Click the links in the README

Files to reproduce
N/A

Expected behavior
N/A

Environment

• OS: [e.g. iOS] Firefox
• source-map-explorer Version [e.g. 2.0]

Additional context
Add any other context about the problem here.