Update CODEOWNERS (#569)

Remove smart contract codeowners, change to default

Move SDKs to Developer platform

Author: gregnazario

CODEOWNERS

@@ -11,7 +11,4 @@ apps/nextra/pages/en/network/nodes/** @rustielin @aptos-labs/prod-eng
 apps/nextra/pages/en/build/indexer/** @banool
 
 ## SDKs
-apps/nextra/pages/en/build/sdks/** @0xmaayan @gregnazario
-
-## Move
-apps/nextra/pages/en/build/smart-contracts/** @movekevin @gregnazario
+apps/nextra/pages/en/build/sdks/** @gregnazario @aptos-labs/developer-platform