Adding TypeScript to Piranha Playground

[kevtran2]

This PR adds TypeScript support to the playground.

[CLAassistant]

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1 out of 2 committers have signed the CLA.

✅ kevtran2
❌ Kevin Tran

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[ketkarameya]

Hey @kevtran2 thank you for your contribution.
I do not have a deep understanding for this part of the code, but does adding the typescript option work ? did u try to use the playground ?

[danieltrt]

This is working, I walked Kevin through this change

[kevtran2]

I am having issues merging since CLAassistant wants me to complete two CLAs, one under my github account kevtran2(which I did) and for "Kevin Tran" as a contributor. I don't know why it is confusing my identity as two accounts...