Add naming convention secitons for services/selectors

README.md

@@ -290,6 +290,34 @@ def create_user(
 
 As you can see, this service calls 2 other services - `create_profile` and `send_confirmation_email`
 
+### Naming convention
+
+Naming conventions depend on your taste. It pays off to have a consistent naming convention through out a project.
+
+If we take the example above, our service is named `create_user`. The pattern is - `<action>_<entity>`.
+
+What we usually prefer in our projects, again, depending on taste, is `<entity>_<action>` or with the example above: `user_create`. This seems odd at first, but it has few nice features:
+
+* Namespacing. It's easy to spot all services starting with `user_` and it's a good idea to put them in a `users.py` module.
+* Greppability. Or in other words, if you want to see all actions for a specific entity, just grep for `user_`.
+
+A full example would look like this:
+
+```python
+def user_create(
+    *,
+    email: str,
+    name: str
+) -> User:
+    user = User(email=email)
+    user.full_clean()
+    user.save()
+
+    profile_create(user=user, name=name)
+    confirmation_email_send(user=user)
+
+    return user
+```
 
 ## Selectors
 
@@ -314,6 +342,11 @@ def get_users(*, fetched_by: User) -> Iterable[User]:
 
 As you can see, `get_visible_users_for` is another selector.
 
+
+### Naming convention
+
+Read the section in services. Same rules apply here.
+
 ## APIs & Serializers
 
 When using services & selectors, all of your APIs should look simple & identical.