Add nightly job for doc build

Signed-off-by: Karl Zhang <karl.zhang@arm.com>
Change-Id: I2f78e6ad021629bd7dfbda461c9ef625f34792d2
diff --git a/tf-m-build-docs-nightly.yaml b/tf-m-build-docs-nightly.yaml
new file mode 100644
index 0000000..2a6145f
--- /dev/null
+++ b/tf-m-build-docs-nightly.yaml
@@ -0,0 +1,85 @@
+#-------------------------------------------------------------------------------
+# Copyright (c) 2020, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+#-------------------------------------------------------------------------------
+
+- job:
+    name: tf-m-build-docs-nightly
+    description: 'Builds documentation from repo by nightly'
+    project-type: pipeline
+    disabled: false
+    sandbox: true
+    concurrent: true
+    properties:
+      - build-discarder:
+          days-to-keep: 15
+          num-to-keep: 45
+    triggers:
+      - timed: 'H 21 * * *'
+    parameters:
+      - string:
+          name: 'GERRIT_REFSPEC'
+          default: 'refs/heads/master'
+          description: |
+            For use when triggering with unmerged Gerrit changes.
+      - string:
+          name: 'GERRIT_BRANCH'
+          default: 'master'
+          description: |
+            For use when triggering with unmerged Gerrit changes.
+      - string:
+          name: 'GERRIT_HOST'
+          default: ''
+          description: |
+            For use when triggering with unmerged Gerrit changes.
+      - string:
+          name: 'GERRIT_PATCHSET_REVISION'
+          default: ''
+          description: |
+            For use when triggering with unmerged Gerrit changes.
+      - string:
+          name: 'GERRIT_CHANGE_NUMBER'
+          default: ''
+          description: |
+            For use when triggering with unmerged Gerrit changes.
+      - string:
+          name: 'CI_SCRIPTS_REPO'
+          default: 'https://review.trustedfirmware.org/ci/tf-m-ci-scripts'
+      - string:
+          name: 'CODE_REPO'
+          default: 'https://review.trustedfirmware.org/TF-M/trusted-firmware-m'
+      - string:
+          name: 'MBEDCRYPTO_VERSION'
+          default: 'mbedcrypto-3.0.1'
+      - string:
+          name: 'MBEDCRYPTO_URL'
+          default: 'https://git.trustedfirmware.org/mirror/mbed-crypto.git'
+      - string:
+          name: 'MCUBOOT_VERSION'
+          default: 'v1.6.0'
+      - string:
+          name: 'MCUBOOT_URL'
+          default: 'https://git.trustedfirmware.org/mirror/mcuboot.git'
+      - string:
+          name: 'CMSIS_VERSION'
+          default: '5.5.0'
+      - string:
+          name: 'TFM_TESTS_URL'
+          default: 'https://git.trustedfirmware.org/TF-M/tf-m-tests.git'
+      - string:
+          name: 'TFM_TESTS_REFSPEC'
+          default: 'refs/heads/master'
+      - string:
+          name: 'CI_SCRIPTS_BRANCH'
+          default: 'master'
+    pipeline-scm:
+      scm:
+        - git:
+            url: '$CI_SCRIPTS_REPO'
+            branches:
+            - '$CI_SCRIPTS_BRANCH'
+            credentials-id: GIT_SSH_KEY
+            wipe-workspace: false
+      script-path: jenkins/build-docs.jpl