fix(babel): replace double quotes with single quotes.

Coding style requires single quotes

Author: SjB

lua/orgmode/babel/tangle.lua

@@ -77,7 +77,7 @@ function Tangle:tangle()
 
     if info.header_args[':mkdirp'] == 'yes' then
       local path = vim.fn.fnamemodify(info.filename, ':h')
-      vim.fn.mkdir(path, "p")
+      vim.fn.mkdir(path, 'p')
     end
 
     if info.name then