Correct flex text type definition

[dlackty]

According to Flex documentation, only one of text or contents needs to be present in flex text.

Be sure to set either one of the text property or contents property. If you set the contents property, text is ignored.

[xingoxu]

Suggested change

	export declare type FlexText = (FlexTextWithText | FlexTextWithContents) &
	export type FlexText = (FlexTextWithText | FlexTextWithContents) &

Besides, Typescript will accept both text & contents in one object. The reason is here:
https://stackoverflow.com/questions/37688318/typescript-interface-possible-to-make-one-or-the-other-properties-required

But anyway, thanks for the type definition.

[dlackty]

Thanks! All the style issues are corrected.

I've read through the stackoverflow post and see an answer describing a way to make Typescript accept only one.