Make left menu section visible by default

[Jeckerson]

It's very hard to see this menu at the first time. Also it is harder to focus when you need to move mouse and navigate between anchors.

Probably would be better to make some button which will toggle display of that menu.

[sergeyklay]

Agree. Not "very", fantastic hard

[niden]

@asokal Can you have a look at this please?