alacritty-theme: don't litter /

Moves the output files from $out/ to $out/share/alacritty-theme/
Without this, ~/.nix-profile/ is filled with alacritty-theme files
when using alacritty-theme from home-manager.

pkgs/by-name/al/alacritty-theme/package.nix

@@ -25,7 +25,7 @@ stdenvNoCC.mkDerivation (self: {
   sourceRoot = "${self.src.name}/themes";
   installPhase = ''
     runHook preInstall
-    install -Dt $out *.toml
+    install -Dt $out/share/alacritty-theme *.toml
     runHook postInstall
   '';