improve brief description of conf_sig_algs

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 67ca192..6cb7035 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -3777,7 +3777,7 @@
 #endif /* !MBEDTLS_DEPRECATED_REMOVED && MBEDTLS_SSL_PROTO_TLS1_2 */
 
 /**
- * \brief          Configure allowed signature algorithms
+ * \brief          Configure allowed signature algorithms for use in TLS
  *
  * \param conf     The SSL configuration to use.
  * \param sig_algs List of allowed IANA values for TLS 1.3 signature algorithms,