readme for react-multilist-grid

[russgove]

Q	A
Bug fix?	no - yes?
New feature?	no - yes?
New sample?	no - yes?
Related issues?	fixes #X, partially #Y, mentioned in #Z

What's in this Pull Request?

Please describe the changes in this PR. Sample description or details around bugs which are being fixed.

Guidance

You can delete this section when you are submitting the pull request.

• Please update this PR information accordingly. We'll use this as part of our release notes in monthly communications.
• Please target your PR to 'dev' branch.

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[VesaJuvonen]

thx Russell, appreciated.