Typescript types - add more type for `layout` object #3582

Describe the bug

As a user who is adding using G6, I would like to get type completions while I am configuring my layout object Only a subset of the valid options are available. <img width="1244" alt="CleanShot 2022-03-15 at 09 33 36@2x" src="https://user-images.githubusercontent.com/6743796/158426562-07d5ee76-f788-4e2c-9a96-889c39d5a9e7.png">

Your Example Website or App

https://codesandbox.io/s/charming-fast-sbl3og

Steps to Reproduce the Bug or Issue

1. Attempt to type in nodeSpacing or comboPadding or any other valid property that you can pass to the layout object. You will notice that we are not getting intellisense / autocomplete in your IDE / code editor.

Currently only a few properties (5) are exposed on layout the last one is [key: string]: unknown; which allows us to pass other values not defined, this doesnt help us know what is a valid value or not, meaning a user has to leave their text editing experience and go to the documentation to locate the information

Expected behavior

As a user, when I type comboPadding, nodeSpacing or any other valid value to the layout object, my text editor/IDE should autocomplete that value for me.

https://user-images.githubusercontent.com/6743796/158428172-d02c8f5b-f7fb-4ab2-b897-7e83ac70672f.mp4