Mount path mismatch between `readme.md`, and `docker-compose.yml`

[thierrymarianne]

Hi 👋🏼,

Thank you for this amazing project 🤩!

In a nutshell, I've tried running catapulte before
submitting a POST request to http://localhost:3001/templates/user-login/json
without compose (docker only) and the following mount path options :

• with the s suffix (-v ...:templates)
  -> 404 response code ,
• without the s suffix (-v ...:template)
  -> 204 response code.

---

There seems to a mismatch between
the Dockerfile example in the documentation
and the mount path declared in the docker-compose.local.yml configuration file,

As a result, we get a "not found" response by following
the README.md instructions when trying
to send an email based on the user-login template
after replacing /path/to/your/templates with ./template for instance.

[...]
-v /path/to/your/templates:/templates:ro \
[...]

instead of (there is an extra s character in main branch)

[...]
-v /path/to/your/templates:/template:ro \
[...]

I've submitted a short PR
to revise the README.

Please let me know if i'm mistaken about this assumption,
or if you'd like me to make further changes.

Besides, I now wonder if similar changes should not be applied to these lines.