Reorganise entire docs repo

Since we've migrated away from GitHub's Wiki system, we can actually
have our docs organised in a sane structure. Our docs fall into a few
pretty contained categories:

    - alt: documentation for distribution maintainers
           Note that this is *not* for distro-specific documentation.
           We ask that distro maintainers use their distro's own documentation
           infrastructure for that kind of information. This is

    - fw: vendor-controlled firmware and its interfaces. All documentation
          for iBoot, SecureROM, SEPFW, RTKit, WiFi/BT, etc. should go here.
          While m1n1 and U-Boot are "firmware" from the running operating
          system's perspective, they are not firmware from a platform or
          project perspective.

    - hw: documentation for system hardware
        - cpu: anything related to the application processors, e.g. Apple's
               ISA extensions, register definitions, etc.
        - devices: machine-specific documentation, e.g. Mac model numbers
        - peripherals: hardware not integrated into the SoC itself, e.g.
                       webcam, speakers, keyboard, trackpad, etc.
        - soc: functional hardware blocks integrated into the SoC, e.g.
               SMC, video codecs, display controllers, etc.

    - platform: documentation applicable platform-wide, such as the security
                architectire, boot flow, standard SSD partition map, etc.
        - feature-support: feature support lists, separated by SoC generation

    - project: documentation related to the project itself. FAQs, references,
               etc.

    - sw: documentation for all software components that are not considered
          firmware. This includes m1n1, U-Boot, Linux kernel/userspace, etc.

This commit also ensures that all links resolve correctly.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>

Author: chadmed