config(fish): add fish completions for cli tools

dot_config/fish/functions/fish_title.fish

@@ -0,0 +1,8 @@
+function fish_title
+    # Show a short hostname over SSH, otherwise just the current directory.
+    if set -q SSH_TTY
+        echo (prompt_hostname | string sub -l 10):(prompt_pwd)
+    else
+        prompt_pwd
+    end
+end