Major overhaul:

- transition to `pyproject.toml` config
- include license (Apache-2.0)
- add dev tools
- add documentation config (`mkdocs` based)
- turn `README.md` into a symlink to docs `index.md`
- add convenience scripts for testing and linting

pyproject.toml

@@ -1,6 +1,99 @@
+#####################
+# Python packaging: #
+
 [build-system]
-requires = [
-    "setuptools>=42",
-    "wheel"
+requires = ["setuptools", "setuptools-scm"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "${REPO_NAME}"
+description = "${REPO_DESCRIPTION}"
+authors = [
+    { name = "${REPO_OWNER_TITLE}", email = "mail@PLACEHOLDER.to" },
+]
+maintainers = [
+    { name = "${REPO_OWNER_TITLE}", email = "mail@PLACEHOLDER.to" },
+]
+requires-python = ">=3.9, <4.0"
+keywords = [
+
+]
+license = { text = "Apache Software License Version 2.0" }
+classifiers = [
+    "Development Status :: 4 - Beta",
+    "Programming Language :: Python :: 3 :: Only",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Operating System :: OS Independent",
+    "License :: OSI Approved :: Apache Software License",
+#    "Intended Audience :: Developers",
+#    "Framework :: AsyncIO",
+#    "Topic :: Internet",
+]
+dynamic = [
+    "dependencies",
+    "readme",
+    "version",
+]
+
+[project.optional-dependencies]
+full = [
+
+]
+dev = [
+    "black",
+    "build",
+    "coverage",
+    "flake8",
+    "mkdocs-material",
+    "mkdocstrings[python]",
+    "mypy",
+]
+
+[project.urls]
+repository = "https://github.com/${REPO_OWNER_LOWER}/${REPO_NAME_LOWER}"
+bug_tracker = "https://github.com/${REPO_OWNER_LOWER}/${REPO_NAME_LOWER}/issues"
+documentation = "http://${REPO_OWNER_LOWER}.github.io/${REPO_NAME_LOWER}"
+
+[tool.setuptools.dynamic]
+dependencies = { file = "requirements/common.txt" }
+readme = { file = ["README.md"] }
+version = {attr = "PACKAGE_NAME_PLACEHOLDER.__version__"}
+
+#########
+# Mypy: #
+
+[tool.mypy]
+files = "src/"
+warn_unused_configs = true
+strict = true
+show_error_codes = true
+plugins = [
+
+]
+
+#############
+# Coverage: #
+
+[tool.coverage.run]
+source = [
+    "src/",
+]
+branch = true
+command_line = "-m tests"
+omit = [
+    ".venv*/*",
+]
+
+[tool.coverage.report]
+show_missing = true
+skip_covered = false
+exclude_lines = [
+    "if TYPE_CHECKING:",
+    '''if __name__ == ['"]__main__['"]:''',
+    "@overload",
+]
+omit = [
+    "tests/*",
 ]
-build-backend = "setuptools.build_meta"