message: docs: mention GURU overlay in installation instructions
diff: @@ -174,7 +174,16 @@ sudo dnf install bottom
  ### Gentoo
  -Available in [dm9pZCAq overlay](https://github.com/gentoo-mirror/dm9pZCAq)
  +Available in [GURU](https://wiki.gentoo.org/wiki/Project:GURU) and [dm9pZCAq](https://github.com/gentoo-mirror/dm9pZCAq) overlays
  +
  +```bash
  +sudo eselect repository enable guru
  +sudo emerge --sync guru
  +echo "sys-process/bottom" | sudo tee /etc/portage/package.accept_keywords/10-guru
  +sudo emerge sys-process/bottom::guru
  +```
  +
  +or
  ```bash
  sudo eselect repository enable dm9pZCAq
  