Improvements needed for DT-OTIC and NCTU deploys

- Add text/debug boot mode
- Add ability to specify network interfaces manually during install
- Documentation fixes
- Run 'apt update' in prepare, to help pass CI

Change-Id: Ie341d003b499ef2d22f2d58c38eb41016df93d5a
diff --git a/molecule/default/prepare.yml b/molecule/default/prepare.yml
new file mode 100644
index 0000000..387f291
--- /dev/null
+++ b/molecule/default/prepare.yml
@@ -0,0 +1,15 @@
+---
+# pxeboot molecule/default/verify.yml
+#
+# SPDX-FileCopyrightText: © 2020 Open Networking Foundation <support@opennetworking.org>
+# SPDX-License-Identifier: Apache-2.0
+
+
+- name: Prepare for pxeboot role
+  hosts: all
+
+  pre_tasks:
+
+    - name: update apt cache
+      apt:
+        update_cache: true