bootloader Rewrite

[garnerlogan65]

This article is in need of a massive reorganization, and potential re-write. While it has most of the pertinent information, it is not laid out in a clear and concise manner. I will likely do the re-write.

Changes needed:

• place UEFI/legacy echo command at top, to ensure that the user knows this is the first step.
• edit live disk section to include the live disk article for non Pop systems.
• rewrite language in partition section to specify more clearly what the user needs to do and that the numbering scheme may vary.
• clarify typical cases (GRUB is used on Ubuntu / Pop MBR). systemd-boot used on Pop UEFI installs)
• potentially explain what the command sections do with # comments?
• place encrypted disk section farther up? (Do you have an encrypted disk on Pop!_OS? Follow these steps first to mount your drive...)
• Simplify chroot section, we have the login-from-live-disk article.

Alternatively, could we potentially make this more streamlined to fit into the article. The organization feels off to me.

-Under troubleshooting, the immediate section is "chroot" as is the section before. Rename "Exec format error?" -Conclusion: "If your OS is still not booting, and you have System76 hardware, please submit a support ticket."