feat(tarot): expand spread descriptions and add good-for guidance

Each spread now has a fuller description and a "Good for:" line
explaining what kinds of questions it suits best.

Also gitignores tarot/generate.py and tarot/.venv/ to prevent
accidental commits of local tooling.

✨ This commit was made with love from Hikari~ 🌸

.gitignore

@@ -1 +1,3 @@
-*.json
+*.json
+tarot/generate.py
+tarot/.venv/