Visual Studio Code - Auto Hiding Explorer

You cannot currently auto-hide the explorer. The GitHub issue tracking this is #3742.

ctrl+b (Windows, Linux), cmd+b (OS X) is the keybinding to manually toggle the side bar.

Went ahead and made an extension for this:

It's not perfect -- it only closes the side-bar when the user changes the selection (eg, clicking or dragging at a new location) -- but it achieves the basic function.

Built-in support is still ideal, but this should help until then.