Extension window size overflows #188

Describe the bug
The extension window is scrollable even though there is enough screen space to render it. Also, content is hidden behind the scrollbars.

To Reproduce
Open the extension window by clicking the extension icon.

Expected behavior
The extension window is big enough so it doesn't need scrolling.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop

• OS: Windows 10, 10.0.18363 Build 18363 (1909 is last major update)
• Browser: Firefox Dev Edition
• Version 79