add a first version for a typescript guideline

[andreineculau]

• Fixes:
• Breaking change: [ ]

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• add reference to https://basarat.gitbooks.io/typescript/
• add reference to interface equivalents for classes
• add reference for interface equivalents for tuples
• prefer leading & or | in multiline intersection or union types Union and intersection types with leading operator microsoft/TypeScript#12386
• indentation issues for multiline generics [indent] behavior changed for multiline generic type parameters typescript-eslint/typescript-eslint#455 (comment)

[tobiiasl]

Great work! A very nice introduction for developers at all levels. I have only read part of it so far (will continue with "Amend modules and interfaces" next time).

I mostly had suggestions for possible improvements on how to make the text easier to grasp.

[andreineculau]

@tobiiasl thanks!