Add OpenGL ES support

[aartoni]

This should be implemented in swayvnc-chrome, see this issue for more details.

@stephanlensky I'd let users enable this via an env var and then read it in the Docker entrypoint script. One more thing, can you allow issues to be opened on the swayvnc-chrome repo?

[stephanlensky]

can you allow issues to be opened on the swayvnc-chrome repo?

Done, sorry about that