Clean up sdist and build instructions

{{ cookiecutter.namespace }}/pyproject.toml

@@ -50,16 +50,9 @@ dependencies = [
 # "Discussions" = "https://github.com/organization/package/discussions"
 # "Changelog" = "https://github.com/organization/package/blob/main/CHANGELOG.md"
 
-[tool.hatch.build]
-include = [
-    "src/pynwb",
-    "spec/{{ cookiecutter.namespace }}.extensions.yaml",
-    "spec/{{ cookiecutter.namespace }}.namespace.yaml",
-]
-exclude = [
-    "src/pynwb/tests",
-]
-
+# Include only the source code under src/pynwb/{{ cookiecutter.py_pkg_name }} and the spec files under spec.
+# Install the spec files in the wheel under the {{ cookiecutter.py_pkg_name }} package.
+# {{ cookiecutter.py_pkg_name }}/__init__.py will look there first for the spec files.
 [tool.hatch.build.targets.wheel]
 packages = [
     "src/pynwb/{{ cookiecutter.py_pkg_name }}",
@@ -70,13 +63,9 @@ packages = [
 "spec" = "{{ cookiecutter.py_pkg_name }}/spec"
 
 [tool.hatch.build.targets.sdist]
-include = [
-    "src/pynwb",
-    "spec/{{ cookiecutter.namespace }}.extensions.yaml",
-    "spec/{{ cookiecutter.namespace }}.namespace.yaml",
-    "docs",
+exclude = [
+    ".git*",
 ]
-exclude = []
 
 [tool.pytest.ini_options]
 # uncomment below to run pytest always with code coverage reporting. NOTE: breakpoints may not work