Update README regarding wp-content submodule

README.md

@@ -59,14 +59,32 @@ hugo server &
 
 #### Seeing images on localhost
 
-At the moment (2025-02-12), the images live in a separate repo,
-https://github.com/OBF/wp-content/. If you want to view images in the
-web pages on localhost:1313, you will need to clone that repo and then
-make a symbolic link to it in the content directory of your
-checked-out copy of OBF.github.io.
+At the moment (2025-03-05), historic images live in a large separate repo
+https://github.com/OBF/wp-content/ which is included as a git submodule.
+If you want to view images in the web pages on localhost:1313, you will need
+to also initialise this repository, which is currently setup using the 
+`git submodule` workflow. **By default the `wp-content` submodule is not cloned**
+
+To load it you can run: 
+
+* `cd OBF.github.io/`
+* `git submodule init`
+* `git submodule update`
+
+Getting the files can take a while (the `wp-content` repo is ~500 MB).
 
 This may change.
 
+#### Adding new images
+
+For new images, you can place these into the `static/img` folder of this repository, ideally in a subfolder based on the four digit year.
+
+When compiling the website during the build, Hugo will move everything in `static/` into the website root, i.e. to `open-bio.org/`. This means that when linking images you do not have to include the `static/` as part of the media/image link. 
+
+As an example: A file that resides in `static/img/test-image.jpg` should be linked in the markdown files like this: `![an image](/img/test-image.jpg)`
+
+It is also good practice to name media files with the date you add them/the date of the page/post you want to add them to, e.g. `static/img/2025/2025-03-04-blogpost-image.jpg` (using `yyyy-mm-dd` as the start of the filename).
+
 #### Some other random tips
 
 - To set up a URL redirect, add an alias to the page you want to