Use DataIndex<RecordType> for better constraints?

I'd like to propose this change:

Before:

export declare type DataIndex = string | number | (string | number)[];

After:

export declare type DataIndex<RecordType> = keyof RecordType | number | (keyof RecordType | number)[];

That way, you get full type checking on dataIndex like here:

const columns : ColumnsType<Client>= [
 {
      title: 'Name',
      dataIndex: 'name',   // If 'name' does not exist for type Client, a Typescript error will occur
      key: 'name',
      render: text => <a>{text}</a>
},
]

If you like it, I can send a PR.

Start by locating the DataIndex and ColumnsType type declarations and inspect how dataIndex is used throughout the table types. Compare the proposed generic constraint with existing usages, then verify that valid keys type-check and invalid keys produce TypeScript errors without breaking numeric or array indexes.