message: docs: Add Gentoo installation instructions
diff: @@ -18,6 +18,7 @@ A cross-platform graphical process/system monitor with a customizable interface
  - [AUR](#aur)
  - [Debian (and Debian-based)](#debian)
  - [Fedora/CentOS](#fedoracentos)
  + - [Gentoo](#gentoo)
  - [Nix](#nix)
  - [Homebrew](#homebrew)
  - [Scoop](#scoop)
  @@ -133,6 +134,15 @@ sudo dnf copr enable atim/bottom -y
  sudo dnf install bottom
  ```
  +### Gentoo
  +
  +Available in [dm9pZCAq overlay](https://github.com/gentoo-mirror/dm9pZCAq)
  +```bash
  +sudo eselect repository enable dm9pZCAq
  +sudo emerge --sync dm9pZCAq
  +sudo emerge sys-process/bottom::dm9pZCAq
  +```
  +
  ### Nix
  ```bash
  