docs: adds unifra to RaaS providers list (#451)

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# Description
add unifra to RaaS providers list
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## Additional context

Author: shu-unifra

content/10.zk-stack/20.running/70.raas.md

@@ -35,3 +35,4 @@ Below is a list of RaaS providers that support **ZKsync chain deployment and cus
 - [Caldera](https://www.caldera.xyz/)
 - [QuickNode](https://www.quicknode.com/rollup)
 - [Zeeve](https://www.zeeve.io/appchains/zksync-hyperchains-zkrollups/)
+- [Unifra](https://unifra.io/rollup)