fix: added yandex oath conf to sample configs

config.example.toml

@@ -9,3 +9,7 @@ url = "postgresql+psycopg://username:password@host:port/database"
 [access_token]
 crypto_key = "..."
 expires_in = 86400
+
+[yandex_oauth]
+client_id = "..."
+client_secret = "..."

infrastructure/configs/backend/config.toml

@@ -9,3 +9,7 @@ url = "postgresql+psycopg://postgres:postgres@postgres:5432/postgres"
 [access_token]
 crypto_key = "insecure_token"
 expires_in = 86400
+
+[yandex_oauth]
+client_id = "..."
+client_secret = "..."