docs: remove unavailale api doc links.

Author: m4sterchain

docs/README.md

@@ -53,10 +53,3 @@ permalink: /docs/
 - [Third-Party Dependency Vendoring](../third_party/README.md)
 - [Tools](../tools/README.md)
 - [Types](../types/README.md)
-
-## API References
-
-- [Teaclave SGX SDK](https://teaclave.apache.org/api-docs/sgx-sdk/)
-- [Teaclave Client SDK (Python)](https://teaclave.apache.org/docs/client-sdk-python/)
-- [Crates in Teaclave (Enclave)](https://teaclave.apache.org/docs/crates-enclave/)
-- [Crates in Teaclave (App)](https://teaclave.apache.org/docs/crates-app/)