Refined CSS for docs viewer.

[scudette]

• Images can be opened in a larger modal dialog
• External links must open in a new tab

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

✅ scudette
❌ snyk-bot
_{You have signed the CLA already but the status is still pending? Let us recheck it.}