Fix ruff D400 and improve comment

Follow-up of post merge comments in #170

Author: dalito

template/.pre-commit-config.yaml

@@ -19,7 +19,7 @@ repos:
       - id: yamllint
         args: [-c=.yamllint.yaml]
         exclude: ^\.copier-answers\.yml$
-        verbose: true  # Show warnings but don't fail the commit.
+        verbose: true  # Show warnings.
 
   - repo: https://github.com/codespell-project/codespell
     rev: v2.4.2

template/src/{{project_slug}}/__init__.py.jinja

@@ -1,4 +1,4 @@
-"""{{project_name}}
+"""{{project_name}}.
 
 {{project_description}}
 """