While building this extension I found that VS Code is missing feature parity with Sublime Text. The feature is increasing and decreasing font size.

This is what I see in Sublime Text.

The keyboard shortcut for this in Sublime Text is ctrl++ and ctrl+- on Windows / Linux. The shortcut on Mac is cmd++ and cmd+= to increase font and cmd+- to decrease font.

Note that this feature is closely related to, but not quite the same as zooming in and out.