update readme

README.md

@@ -17,7 +17,9 @@ To add a static page, create a new file in the `/content/page` folder. You can l
 menu defined in `hugo.toml`, either as a top level item, or sub-menu item (by defining its `parent`). Pages can be 
 organised into subfolders as required.
 
-Images should be saved to `static/img`
+Images should be saved to `static/img` which are deployed to a top-level `img` folder. 
+When including links to images, you'll need to set the path to this relative to the page or post you're working in e.g. to link
+to `img/frights_and_bites.png` from `page/social.md`, the path is `../../img/frights_and_bites.png`.
 
 ## Local testing