arthur-tf-sync-repos: import RTD_TOKEN for testing

Signed-off-by: Arthur She <arthur.she@linaro.org>
Change-Id: Ibfedd5738c8a0183d7ea9e8c32d0e1f4457ffeec
diff --git a/arthur-tf-sync-repos.yaml b/arthur-tf-sync-repos.yaml
index 8d804c6..c11f4cb 100644
--- a/arthur-tf-sync-repos.yaml
+++ b/arthur-tf-sync-repos.yaml
@@ -50,3 +50,7 @@
       - text:
           credential-id: openci-bot-github-token
           variable: AUTH_TOKEN
+      - text:
+          credential-id: Trusted_Firmware_ReadTheDocs_Token
+          variable: RTD_TOKEN
+