mount the visual search image into the container

visual_search.jpg is gitignored and excluded by .dockerignore, so the
container had no file at the path rewards_tasks.py uploads and the visual
search task was the one task that could not run in it. Bind mount it from
the project root, where src/random_image_for_visual_search.py writes it.

Also add the blank line the Logging heading needs to render.

README.md

@@ -101,6 +101,14 @@ msedge --user-data-dir="<repo>\data-dir" --profile-directory=Default https://rew
 
 Close every window of that profile afterwards. Chromium allows one process per profile directory, so a window left open on the host stops the container from starting.
 
+**Provide the visual search image on the host too.** `visual_search.jpg` is not in the repository and is not built into the image, so create it once in the project root and the compose file mounts it in:
+
+```sh
+python src/random_image_for_visual_search.py
+```
+
+Without it every other task still runs; only the visual search one fails.
+
 Multiple accounts work the same way in the container:
 
 ```sh
@@ -108,6 +116,7 @@ REWARDS_ACCOUNTS=personal,spare docker compose run --rm rewards-farmer
 ```
 
 `REWARDS_HEADLESS=1` is set in the image. It also works on the host if you want a run with no visible window; the pointer code needs an explicit window size in that mode, which `main.py` sets.
+
 # Logging
 
 The script logs to the console. Two optional environment variables change that:

docker-compose.yml

@@ -27,3 +27,8 @@ services:
     volumes:
       # Keeps the sign-in across container rebuilds.
       - ./data-dir:/app/data-dir
+      # The visual search task uploads this file, which is gitignored and so is
+      # never in the image. Create it first with
+      # `python src/random_image_for_visual_search.py`; a path that does not
+      # exist yet is mounted as an empty directory rather than a file.
+      - ./visual_search.jpg:/app/visual_search.jpg:ro