New comment by st3r4g on void-packages repository

https://github.com/void-linux/void-packages/pull/29115#issuecomment-797648216

Comment:
Trying again with void-runit master and it looks pretty nice. The issues above are solved.
I'll give an overview how it works.
Suppose you have a package for s6-l-i:
```
xbps-install s6-linux-init
```
Installing it will add an alternative for `void-init`:
```
$ xbps-alternatives -g void-init -l
void-init
 - runit-void (current)
  - init:/usr/bin/runit-init
  - halt:/usr/bin/halt-runit
  - poweroff:/usr/bin/poweroff-runit
  - reboot:/usr/bin/reboot-runit
  - shutdown:/usr/bin/shutdown-runit
 - s6-linux-init
  - init:/usr/bin/init-s6
  - halt:/usr/bin/halt-s6
  - poweroff:/usr/bin/poweroff-s6
  - reboot:/usr/bin/reboot-s6
  - shutdown:/usr/bin/shutdown-s6
```
To boot into s6:
```
xbps-alternatives -s s6-linux-init void-init
reboot-runit
```
And to boot back to runit:
```
xbps-alternatives -s runit-void void-init
reboot-s6
```
In case init breaks, `runit-void` is always there so you can always `init=/sbin/runit-init`