docs: add Windows setup README and default Ollama URL to localhost

Add README with Windows clone/run instructions and Ollama model setup.
Default OLLAMA_API_BASE_URL to host.docker.internal so it works out of
the box on the same PC, with comments on pointing it at a remote PC.

Co-authored-by: Claude <claude-code@anthropic.com>

.gitignore

@@ -0,0 +1,8 @@
+# Local environment / secrets
+.env
+.env.*
+!.env.example
+
+# OS / editor cruft
+.DS_Store
+Thumbs.db