Images in www/ folder not accessible from `secure_rmd()`

[merlinoa]

e.g. the following does not work if the below image is in the www folder. We may need to manually addResourcePath() the www/ folder in secure_rmd()

title: "My title"
date: "`r Sys.Date()`"
polished:
  sign_in_page:
    logo: "img/my_image.png"