First-half installation page change.  I wanted to know what you all think before continuing to update the 2nd half of the installation guide.
The biggest changes are the order (flow) of the install guide and OPNsense Importer.

Order:  The page first talks about Image types then jumps to Download & verification (should be closer to the installation section), and then back to installation Media, naming, etc.  The flow in this change is installation images/media, downloading, verifying, and installing.

OPNsense Importer: Complete rewrite to give direction on how to use it.

Removals:
LibreSSL vs OpenSSL
Cut back on the directions for downloading image files, as the previous directions failed after step 2.  Most browsers today download even if you right-click and open in a new tab.
(lands signed and verified in the GUI of the running software)
Updates:
Installation Media adding Image Type column
add openssl checksum step

Rewrote Embedded vs Full section using the suggestions PR #456 .

Corrected /var/log for re-writes

Added more to OPNsense Importer breaking the directions in two: existing  installations vs New

Re-ordered Boot Preparation under Installation Method.

Changed the Section names around.

Some other mirror text exits.

Please tell me if I'm going in an unwanted direction?

ReST edits.  Still learning

Changed Boot Preparation > System Boot Preparation, and updated the section.

Lite touches to Importer section.  Creating flow between Importer and Live environment.

Rewrite Live Environment section.  Thoughts?

Moved the nano Image section.  Re-write of the nano section.

Made some modifications to Live Environment section

Re-write of install to target system to OPNsense Installer

Co-authored-by: Franco Fichtner <franco@lastsummer.de>

Co-authored-by: Franco Fichtner <franco@lastsummer.de>

Co-authored-by: Franco Fichtner <franco@lastsummer.de>

Co-authored-by: Franco Fichtner <franco@lastsummer.de>

Co-authored-by: Franco Fichtner <franco@lastsummer.de>

Co-authored-by: Franco Fichtner <franco@lastsummer.de>

Fixing broken links
updating and improving formatting

Need someone to review the internal comments?  If there is a better way of asking these question please let me know.