removed release notes folder for webhooks release.

[chakkaradeep]

Q	A
content fix?	yes

What's in this Pull Request?

Removed release notes folder from TOC for webhooks release.

[msftclas]

Hi @chakkaradeep, I'm your friendly neighborhood Microsoft Pull Request Bot (You can call me MSBOT). Thanks for your contribution!

It looks like you're a Microsoft contributor (Chakkaradeep (Chaks) Chinnakonda Chandran). If you're full-time, we DON'T require a Contribution License Agreement. If you are a vendor, please DO sign the electronic Contribution License Agreement. It will take 2 minutes and there's no faxing! https://cla.microsoft.com.

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