Add recentPadList in options, disable showing the recent pads

[nono-lqdn]

Describe the bug
There is no way to disable to showing of recent pads

To Reproduce
Steps to reproduce the behavior:

1. Go to main page
2. See error

Expected behavior
Disable the showing of recent pads in the settings, add documentation around this feature.

Screenshots
You may not wish to show the recently created pads.

[erdgeist]

I was worried about it as well, since exposing paths to non-public pads is unacceptable. Digging deeper, I have found that this list is stored in the browser's localStorage and is not gathered in real time from the server:

https://github.com/ether/etherpad-lite/blob/develop/src/static/skins/colibris/index.js#L45

Anyhow, a feature like this definitely needs to be properly communicated and there should be an obvious way to switch it off.

[SamTV12345]

I'll add a switch. It only shows your recent pads. Otherwise you could leak a lot of information and because there is not a possibility to have an account for Etherpad it is not shared between browsers. The use case is you start preparing a pad and want to continue later or you work collaboratively and now want to reread your notes.

[lupa18]

Hi ! Any progress on this?