Add Telegram data source

[hstolte]

The Telegram desktop app has an option "Export Telegram data" as a json (or html) file including chats, contacts, media and a whole lot more...

I will try to integrate it if I find some time ;)

[hstolte]

I started working on this :)

[mholt]

Awesome! Can't wait to review it!

I responded to your email by the way. Let me know here on GitHub if you still have the problem -- just open a new issue.

[mholt]

@hstolte FYI, I've added a new issue template for requesting data sources which will make it easier for whoever implements it. If you could update your original post to use this template, that would be great, thanks!

(In your case, a PR is already open - a WIP - but I'm commenting on all issues like this anyway just to be consistent.)

[mholt]

I went ahead and implemented this in Timelinize (see #84 and also the README for info) but it only supports 1:1 chats, not group chats, due to some limitations in the archive format.