Add first batch of TypeScript declarations

[matei-radu]

This PR adds the first chunk of TypeScript declarations to the existing code base as requested in #39.

Overall I believe these types are imperfect but still a good starting point. Over time we will iterate and improve them through usage and developer feedback.

What is included

The focus is on most of the commonly used features of @scatter-js/core, such as:

• components used to initialize a Scatter dapp (creating a Network object, connect and login methods, etc)
• most of the WALLET_METHODS
• typings for Identity, Account and other objects returned from Scatter

In addition, typings for @scatter-js/eosjs2 and @scatter-js/lynx plugins are added.

What is not included

• Accuracy. The existing code base lacks comments and documentation, so finding out the right types is not trivial. Over time this will, however, improve through feedback from developers.
• Some less commonly used features are still missing types. For now, these are marked as any.
• Some parts rely on existing typings from the eosjs package, mainly the Api and JsonRpc classes. However, I did not take the liberty of adding this package as a peer dependency (maybe @nsjames can tell me if it is ok or not) so for now, those types are replaced with any as well.

[matei-radu]

@AnyPang :smile:

[AnyPang]

@matei-radu It's great! I use it in Egret,and it has the following compiling errors: Error scatter-js/packages/core/types/index.d.ts (144,13): A rest parameter must be of an array type. Error scatter-js/packages/core/types/index.d.ts (144,24): Cannot find name 'Parameters'. Error scatter-js/packages/core/types/index.d.ts (144,57): Cannot find name 'ReturnType'. Maybe the Egret has the lower version of the Typescripts compiler.How should I fix these errors?

[matei-radu]

Thanks for finding this!

I don't know what Egret is but you need TypeScript version 3.1 or above to use these types, which was released more than a year ago.

[nsjames]

Awesome! Gonna go over these tomorrow <3

[nsjames]

So, everything looks good at a glance (haven't pulled locally yet), but how does this handle the dynamically added methods such as ScatterJS.eos()?