feat: ✨ add pyproject.toml classifiers for better discoverability (#290)

# Description

Classifiers help with discoverability.

Closes #251

Needs a quick review.

## Checklist

- [x] Ran `just run-all`

Author: lwjohnst86

template/pyproject.toml.jinja

@@ -16,6 +16,26 @@ license = "MIT"
 license-files = ["LICENSE.md"]
 requires-python = ">=3.12"
 dependencies = []
+# From https://pypi.org/classifiers/
+classifiers = [
+  "License :: OSI Approved :: MIT License",
+
+  # Strict typing, checked via mypy
+  "Typing :: Typed",
+
+  # How mature is this project? Common values are
+  #   3 - Alpha
+  #   4 - Beta
+  #   5 - Production/Stable
+  "Development Status :: 4 - Beta",
+
+  # Indicate who your project is intended for
+  "Intended Audience :: Developers",
+
+  # Specify the Python versions you support here.
+  "Programming Language :: Python :: 3",
+  "Programming Language :: Python :: 3.12",
+]
 
 [project.urls]
 # TODO: Add URLs relevant to the project.