This commit adds a privacy policy feature for new users. When a new user joins, the code reads the privacy policy from the "POLICY.md" file and sends it to the user in chunks of 4096 characters, respecting Telegram's character limit. This ensures that the privacy policy is sent in a readable format without splitting it in the middle of a line.
This commit refactors the `list_birthday` function in `main.py` to sort the birthdays by the remaining time until the next birthday. It introduces a new helper function `sort_close` that calculates the remaining time until the next birthday for each birthday in the list. The birthdays are then sorted based on this calculated value.
