add markdown formatting function

fish/.config/fish/functions/mdfmt.fish

@@ -0,0 +1,9 @@
+function mdfmt
+	for md in $argv
+        pandoc \
+            -f markdown+yaml_metadata_block \
+            -t markdown+yaml_metadata_block \
+            --atx-headers \
+            -o $md $md
+    end
+end