Add documentation to configure the contents of the green section in the bottom left

[sestegra]

The contents of the green section in the bottom left should be configurable.

In fact, when using a frontend proxy like NGINX, code-server is exposed with another address than the bind address (this is the address displayed in the green section in the bottom left). Thus, I need to update that address to the one exposed by NGINX.

[nakkaya]

I also use code-server behind nginx, setting proxy_set_header Host $host; in your reverse proxy conf should change the green bar to correct value.

[sestegra]

@nakkaya Thank you, it works. So, I changed the issue to document this feature.

[bpmct]

didn't know this, very cool!