Add ILLA Cloud to the list

[ILLA Cloud](https://www.illacloud.com/) - ILLA is an open-source low-code platform alternative to Retool and Appsmith for developers to build internal tools in minutes. ([Demo](https://fast-try.illacloud.com/) [Source Code](https://github.com/illacloud/illa-builder)) 

ILLA can also be deployed via docker-compose.
https://github.com/illacloud/deploy-illa-manually