Update DEMO link

### What's done:
* Update DEMO link

README.md

@@ -26,7 +26,7 @@ Now diKTat was already added to the lists of [static analysis tools](https://git
 
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-|[Codestyle](info/guide/diktat-coding-convention.md)|[Inspections](info/available-rules.md) | [Examples](examples) | [Demo](https://ktlint-demo.herokuapp.com) | [White Paper](wp/wp.pdf) | [Groups of Inspections](info/rules-mapping.md) |
+|[Codestyle](info/guide/diktat-coding-convention.md)|[Inspections](info/available-rules.md) | [Examples](examples) | [Demo](https://saveourtool.com/#/demo/diktat) | [White Paper](wp/wp.pdf) | [Groups of Inspections](info/rules-mapping.md) |
 
 ## Why should I use diktat in my CI/CD?