message: Add Gentoo install dependencies
  While Gentoo was listed in the table of contents of the INSTALL.md, the
  instructions to install the build dependencies were missing.
  This adds the emerge command necessary to install all dependencies of
  Alacritty (other than Rust) so building from source without the overlay
  is possible.
diff: @@ -156,7 +156,7 @@ Alacritty. Here's a `eopkg` command that should install all of them. If
  something is still found to be missing, please open an issue.
  ```sh
  -sudo eopkg install fontconfig-devel
  +eopkg install fontconfig-devel
  ```
  #### NixOS/Nixpkgs
  @@ -168,6 +168,16 @@ dependencies on [NixOS](https://nixos.org).
  nix-shell -A alacritty '<nixpkgs>'
  ```
  +#### Gentoo
  +
  +On Gentoo, you need a few extra libraries to build Alacritty. The following
  +command should install all of them. If something is still found to be missing,
  +please open an issue.
  +
  +```sh
  +emerge --onlydeps x11-terms/alacritty
  +```
  +
  #### Windows
  On windows you will need to have the `{architecture}-pc-windows-msvc` toolchain
  