Add a Button to Hide Left Panel

I am currently working on the couch with my laptop without access to the plethora of additional monitors in my office.

I see there is an option in the little 3 dot drop down list to "hide right panel" but there is no option to hide the left panel.

Feels very claustrophobic having both of them up, especially when I have all the elements i need on the page, i just need to add copy and format.