Add configuration template files (.env.example, .dockerignore)

Added essential configuration templates that were missing from the
repository due to overly restrictive .gitignore patterns.

Changes to .gitignore:
- Added negation patterns for .env.example files
- Added negation patterns for .dockerignore files
- These are safe template files with placeholder values

Files added:
- .env.example (root): Main environment configuration template
- reports-app/backend/.env.example: Backend configuration template
- reports-app/frontend/.env.example: Frontend configuration template
- reports-app/telegram-bot/.env.example: Telegram bot config template
- reports-app/telegram-bot/.dockerignore: Docker build exclusions

These template files help developers quickly set up their local
development environment by copying and customizing them.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

reports-app/telegram-bot/.dockerignore

@@ -0,0 +1,66 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+*.egg-info/
+dist/
+build/
+*.egg
+
+# Virtual environments
+venv/
+env/
+ENV/
+.venv
+
+# Environment files
+.env
+.env.local
+.env.*.local
+
+# SQLite database files
+*.db
+*.db-shm
+*.db-wal
+data/*.db
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# Testing
+.pytest_cache/
+.coverage
+htmlcov/
+.tox/
+
+# Git
+.git/
+.gitignore
+.gitattributes
+
+# Documentation
+*.md
+docs/
+
+# Docker
+Dockerfile
+.dockerignore
+docker-compose*.yml
+
+# CI/CD
+.github/
+.gitlab-ci.yml
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Logs
+*.log
+logs/