Add lemon drizzle cake recipe (#4688)

## Description:

Adds `resources/lemon-drizzle.md`, a markdown recipe for a classic lemon
drizzle cake (ingredients, method, and tips).

This is a standalone documentation/content file — no code, UI, or game
logic is touched.

## Please complete the following:

- [ ] I have added screenshots for all UI updates — N/A, no UI changes
- [ ] I process any text displayed to the user through translateText()
and I've added it to the en.json file — N/A, no in-game user-facing text
- [ ] I have added relevant tests to the test directory — N/A, no code
changes

---
_Generated by [Claude
Code](https://claude.ai/code/session_01Jt1cb7ep49UDEbX9SbRH6Q)_

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

resources/lemon-drizzle.md

@@ -0,0 +1,47 @@
+# Lemon Drizzle Cake
+
+A classic British loaf cake: a light, moist sponge soaked with a tangy lemon
+syrup and finished with a crunchy sugar crust.
+
+**Prep:** 20 minutes · **Bake:** 45–50 minutes · **Serves:** 8–10
+
+## Ingredients
+
+### For the sponge
+
+- 225g unsalted butter, softened
+- 225g caster sugar
+- 4 large eggs
+- 225g self-raising flour
+- 1 tsp baking powder
+- Zest of 2 lemons
+- 2 tbsp milk
+
+### For the drizzle topping
+
+- Juice of 2 lemons (about 6 tbsp)
+- 85g granulated sugar
+
+## Method
+
+1. Preheat the oven to 180°C (160°C fan / 350°F) and line a 900g (2lb) loaf
+   tin with baking parchment.
+2. Beat the butter and caster sugar together until pale and fluffy.
+3. Add the eggs one at a time, beating well after each and adding a spoonful
+   of the flour if the mixture starts to curdle.
+4. Fold in the remaining flour, baking powder, and lemon zest, then stir in
+   the milk to loosen to a soft dropping consistency.
+5. Spoon the batter into the prepared tin and level the top. Bake for 45–50
+   minutes, until golden and a skewer inserted into the centre comes out clean.
+6. While the cake bakes, mix the lemon juice and granulated sugar to make the
+   drizzle. Do not let it fully dissolve — the sugar should stay grainy.
+7. Prick the warm cake all over with a skewer while still in the tin, then
+   spoon the drizzle evenly over the top so it soaks in and the sugar forms a
+   crust.
+8. Leave to cool completely in the tin before removing and slicing.
+
+## Tips
+
+- Swap lemons for limes, or add poppy seeds to the batter for variety.
+- The cake keeps well in an airtight container for up to 3 days and freezes
+  well without the drizzle.