Add English translations for all 379 recipe and tip files

Use dotlang AI translation (aiursoft-instruct:latest via Ollama) to
translate all Chinese content to English under en/ subfolder:
- en/dishes/: all recipe categories (aquatic, breakfast, condiment,
  dessert, drink, meat_dish, semi-finished, soup, staple, vegetable_dish)
- en/tips/: learn/ and advanced/ cooking guides
- en/README.md, en/CONTRIBUTING.md, en/CODE_OF_CONDUCT.md

The mkdocs-static-i18n plugin (docs_structure: folder) serves Chinese
at the root and English at /en/, with a language switcher in the UI.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

en/dishes/vegetable_dish/雷椒皮蛋.md

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+# Recipe for Lei Jiao Preserved Egg
+
+Lei Jiao Preserved Egg is a very simple cold appetizer that pairs well with rice. The preparation is straightforward, and the ingredients are common. Although the final presentation may not be visually appealing, it is one of the ultimate dishes for beating the summer heat and enhancing your appetite.
+
+Estimated Cooking Difficulty: ★★
+
+## Essential Ingredients and Tools
+
+- Preserved eggs (Century eggs)
+- Long green peppers (sometimes called thread peppers; referred to as "green peppers" hereafter)
+- Green onions (scallions)
+- Garlic
+- Millet peppers (optional)
+- Cooking oil
+- Light soy sauce
+- Aged black vinegar
+- White sugar
+- Sesame oil
+- A deep small iron basin
+
+## Measurements
+
+Per serving:
+
+- Preserved eggs: 2
+- Green peppers: 4 (10-15cm long, 2-4cm wide)
+- Green onions: Approximately 10cm (green parts are best)
+- Garlic: 3-4 cloves
+- Cooking oil: 10-20ml
+- Light soy sauce: 15-20ml
+- Aged black vinegar: 15-20ml
+- White sugar: 6-10g
+- Sesame oil: 5-7ml
+- Millet peppers: 3-4 pieces
+
+## Instructions
+
+- Wash the green peppers, remove the stems, slice them open along the side, remove the seeds, and press them flat on a cutting board. Set aside. (It is crucial to remove the seeds, otherwise they may burst in the pan.)
+- Cut the green onions into 0.5cm pieces. Set aside.
+- Peel the garlic and mince it. Set aside.
+- Peel the preserved eggs. Set aside.
+- Cut the millet peppers into 5-10mm pieces. Set aside.
+- Heat a pan and add 10-20ml of cooking oil.
+- Add all the green peppers. Reduce the heat to maintain a low temperature and pan-fry until the peppers become soft (you can test with chopsticks; they should pierce through easily).
+- Turn off the heat and transfer the preserved eggs and green peppers into the small iron basin.
+- Method 1: If you have a rolling pin and don't mind the noise affecting your neighbors: Use one end of the rolling pin to pound the preserved eggs and green peppers in the basin until they are mixed (optional).
+- Method 2: Tear the green peppers by hand into strips approximately 0.5cm wide, and mash the preserved eggs with a fork (optional).
+- Add the millet peppers.
+- Pour in the light soy sauce, aged black vinegar, white sugar, sesame oil, and any other reserved ingredients.
+- Mix evenly.
+
+## Additional Notes
+
+If you encounter any issues or have suggestions for improvement while following this guide, please submit an Issue or Pull request.