Add guide how to use this package

[vitonsky]

Hi, I tried to use this library, but it is absolutely not possible with no any guideline.

Currently i can found only generated SDK API http://matrix-org.github.io/matrix-js-sdk/ that is pretty useless, because does not explain any concepts, any high level library design and does not provide any information about typical use cases.

I tried to implement a trivial scenario where a bot automatically join to any chat and respond with echo. But i have a lot of problems and questions like

• how i can get messages? okay, it looks i have to listen events and filter it by type m.room.message
• why i don't see any messages? I know that i sent it to bot. Ohh, okay, it looks this SDK can't decrypt it, it make sense, how i can setup cryptography?
• okay, I've installed olm and i do (global as any).Olm = olm.default which is pretty bad design, but how I can setup cryptography from my recovery key?

Finally, i decided to pause my exploration of this SDK, because it have a pretty low quality due to lack of documentation.

Could you provide some guide with:

• SDK high level design explanation
• trivial examples, like "echo client that join invites and answer to ecnrypted messages"