Change syntax and custom mapping

README.md

@@ -10,8 +10,8 @@ You need to map it according to your preference.
 
 Here's a quick example:
 
-```vimscript
+```vim
 " OpenUrl.nvim binding
-nnoremap <leader>b :call OpenUrl#UnderCursor()<CR>
+nnoremap <leader>e :call OpenUrl#UnderCursor()<CR>
 ```