Add additional OS installer images

- Debian 11, Ubuntu 20.04, and OpenBSD 7.0 images
  - Menu is too long, so added pxeboot_boot_images list to determine
    which images to download/include in menu
- Update versions and checksums downloaded for existing images, and use
  version specific paths where applicable.
- Update boot parameters to better support EFI booting
- Update galaxy metadata

Change-Id: Iab6d4385489458ff0e4491c4b1de544b442c2622
diff --git a/.reuse/dep5 b/.reuse/dep5
index 36ce305..40fef72 100644
--- a/.reuse/dep5
+++ b/.reuse/dep5
@@ -1,5 +1,5 @@
 Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
 
-Files: .cookiecutter_params.json VERSION .gitreview
+Files: .cookiecutter_params.json VERSION .gitreview README.md
 Copyright: 2020 Open Networking Foundation
 License: Apache-2.0