Add Telegram Bot API support to FAKE

[Jackhammer88]

Description

This PR introduces a new API module, Fake.Api.Telegram, allowing FAKE to send messages via Telegram Bot API.
This enables FAKE users to integrate Telegram notifications into CI/CD pipelines.

Fixes: N/A (no related issue, but can be linked if necessary)

TODO

New API documentation added (Fake.Api.Telegram)

• Module linked in the "side navigation" (docs/data.json)
• Module placed in the correct namespace (Fake.Api.TelegramBot)
• Module added to Fake.sln (dotnet sln Fake.sln add src/app/Fake.Api.TelegramBot/Fake.Api.TelegramBot.fsproj)
• Follows FAKE API Design Guidelines
• Unit or integration test does not exist because it requires a bot token, which is sensitive information and cannot be hardcoded in tests.