Realign pages to link to release assets

[nikitawootten-nist]

This PR addresses #27 utilizing meta-redirects to release assets generated as part of https://github.com/usnistgov/OSCAL-Reference/issues/2.

It also updates wording on the release tutorial tool page

NOTE: this change depends on the following conditions:

• [x] Meta redirects are live via https://github.com/usnistgov/OSCAL-Reference/issues/2
• [x] Updated build and usage instructions are live in main via https://github.com/usnistgov/OSCAL/pull/1865 (edit: develop will be merged at the same time the next OSCAL release happens so this is not a concern)