config(fish): add fish completions for cli tools

dot_config/fish/functions/mdp.fish

@@ -0,0 +1,10 @@
+# ~/.config/fish/functions/mdv.fish
+function mdp -d "Interactive Markdown selector and previewer"
+    # Find markdown files up to 3 directories deep
+    set -l file (fd --type f --extension md --max-depth 3 | fzf --preview 'mdfried {}' --preview-window=right:60%:wrap)
+
+    # Execute mdfried on the selected file if one was chosen
+    if test -n "$file"
+        mdfried "$file"
+    end
+end