chore: Add the note for animation engine license (#5351)

Add proprietary license for animations engine

## Description

1. What is this PR about (link the issue and add a short description)

## Steps for reproduction

1. click button
2. expect xyz

## Code Review

- [ ] hi @kof, I need you to do
  - conceptual review (architecture, feature-correctness)
  - detailed review (read every line)
  - test it on preview

## Before requesting a review

- [ ] made a self-review
- [ ] added inline comments where things may be not obvious (the "why",
not "what")

## Before merging

- [ ] tested locally and on preview environment (preview dev login:
0000)
- [ ] updated [test
cases](https://github.com/webstudio-is/webstudio/blob/main/apps/builder/docs/test-cases.md)
document
- [ ] added tests
- [ ] if any new env variables are added, added them to `.env` file

Author: kof

README.md

@@ -28,3 +28,8 @@
 <a href="https://www.lost-pixel.com/"><img src="https://user-images.githubusercontent.com/29632358/168112844-77e76a0d-b96f-4bc8-b753-cd39f4afd428.png" width="50" height="50" alt="Lost Pixel" /></a>
 
 Thanks to [Lost Pixel](https://www.lost-pixel.com/) for providing the visual testing platform that helps us review UI changes and catch visual regressions.
+
+## License
+
+- **Webstudio core** (all functionality in this repository) is free/open-source under AGPL-3.0-or-later.
+- **sdk-components-animation** package (optional) is proprietary. You must accept the Webstudio, Inc. EULA located in [sdk-components-animation/LICENSE](./packages/sdk-components-animation/LICENSE) before using it.