docs: add class-level docstring to PesaChatBot

pesachat-bot/pesachat_bot/__init__.py

@@ -0,0 +1,21 @@
+from __future__ import annotations
+
+
+class PesaChatBot:
+    """Telegram bot for cross-border remittance powered by the Stellar network.
+
+    Handles incoming Telegram updates, routes commands to the appropriate
+    handlers, and delegates all on-chain operations to *pesachat-core* via HTTP.
+
+    Args:
+        token: Telegram Bot API token issued by @BotFather.
+        core_url: Base URL of the running pesachat-core service
+            (e.g. ``http://localhost:8000``).
+        locale: BCP-47 language tag used for localised response strings.
+            Defaults to ``"en"``.
+    """
+
+    def __init__(self, token: str, core_url: str, locale: str = "en") -> None:
+        self.token = token
+        self.core_url = core_url
+        self.locale = locale