chore: Add aztec not evm compatbile on front page of docs (#11558)

Way too many times we get ethereum's large app or infra builders who
check our docs and not 100% sure if aztec is evm compatible or no

it wastes their time and ours. So this makes it obvious in the front
page

docs/docs/index.mdx

@@ -20,6 +20,8 @@ On Ethereum today, everything is publicly visible, by everyone. In the real worl
 - composability between private/public execution and private/public state
 - public and private messaging with Ethereum
 
+To make this possible, Aztec is *not EVM compatible* and is extending the Ethereum ecosystem by creating a new alt-VM! 
+
 To learn more about how Aztec achieves these things, check out the [Aztec concepts overview](/aztec/concepts_overview).
 
 ## Start coding
@@ -46,4 +48,4 @@ To learn more about how Aztec achieves these things, check out the [Aztec concep
      Learn the core concepts that make up the Aztec Protocol
     </CardBody>
   </Card>
-</div>
+</div>