fix: Improve .gitignore and re-add config file

- Improves organization and removes extra junk files.

- Unignores *.yaml files such as config.yaml from the /checkpoints/ directory since we need that file.

.gitignore

@@ -1,12 +1,31 @@
-venv/
-__pycache__
-*.egg-info
-*.DS_Store
+# Development Tools.
+.mypy_cache/
+.ruff_cache/
+__pycache__/
 .idea/
 .vscode/
-checkpoints/*
-outputs/
-build/
+
+# Environments.
+.venv*/
+venv*/
+conda_env*/
+
+# Python Bytecode.
 *.py[cod]
+
+# Distribution/Packaging.
+/build/
+/dist/
 *.egg-info/
-.venv
+.pypirc
+
+# Operating System Junk.
+*.DS_Store
+Thumbs.db
+desktop.ini
+
+# IndexTTS.
+/cache/
+/checkpoints/*
+!/checkpoints/*.yaml
+/outputs/