add atuin initialization

.config/fish/config.fish

@@ -2,6 +2,11 @@ if status is-interactive
     fish_add_path ~/.cargo/bin
     fish_add_path ~/.local/bin
 
+    if command -q atuin
+        atuin init fish | source
+        atuin gen-completions --shell fish | source
+    end
+
     # bat
     if command -q bat
         alias cat="bat -pp"