Add initial project structure for Telegram bot

- Created Docker configuration files for development and production.
- Added Dockerfile for building the bot image.
- Implemented configuration loading from environment variables.
- Developed main application logic and command handlers.
- Included README with setup instructions and usage details.
- Added .gitignore and .dockerignore files to exclude unnecessary files.
- Provided example environment file (.env.example) for bot token configuration.
- Established basic error handling for the bot.

handlers/__init__.py

@@ -0,0 +1,10 @@
+"""Expose a single register_handlers(app) that registers all handlers."""
+from telegram.ext import Application
+
+from . import commands, errors
+
+
+def register_handlers(app: Application) -> None:
+    app.add_handler(commands.start_handler)
+    app.add_handler(commands.help_handler)
+    app.add_error_handler(errors.error_handler)

handlers/commands.py

@@ -0,0 +1,21 @@
+"""Command handlers: /start, /help (and placeholder for more)."""
+from telegram import Update
+from telegram.ext import CommandHandler, ContextTypes
+
+
+async def start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    if update.message:
+        await update.message.reply_text("Hello! I'm your bot. Use /help to see available commands.")
+
+
+async def help_cmd(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    if update.message:
+        await update.message.reply_text(
+            "Available commands:\n"
+            "/start - Start the bot\n"
+            "/help - Show this help"
+        )
+
+
+start_handler = CommandHandler("start", start)
+help_handler = CommandHandler("help", help_cmd)

handlers/errors.py

@@ -0,0 +1,13 @@
+"""Global error handler: log exception and notify user."""
+import logging
+
+from telegram import Update
+from telegram.ext import ContextTypes
+
+logger = logging.getLogger(__name__)
+
+
+async def error_handler(update: object, context: ContextTypes.DEFAULT_TYPE) -> None:
+    logger.exception("Exception while handling an update")
+    if isinstance(update, Update) and update.effective_message:
+        await update.effective_message.reply_text("Something went wrong. Please try again later.")