config(fish): add fish completions for cli tools

dot_config/fish/functions/cd.fish

@@ -0,0 +1,20 @@
+function cd --description 'cd with zoxide fallback, else builtin cd'
+    if test (count $argv) -eq 0
+        builtin cd $HOME
+    else if test "$argv[1]" = '-'
+        builtin cd -
+    else if builtin cd $argv[1] 2>/dev/null
+        # exact path resolved, nothing else to do
+    else if type -q zoxide
+        set -l target (zoxide query -- $argv[1] 2>/dev/null)
+        if test -n "$target"
+            builtin cd $target
+        else
+            builtin cd $argv[1]  # let builtin cd surface the real error
+        end
+    else
+        builtin cd $argv[1]
+    end
+
+    type -q zoxide; and zoxide add $PWD
+end