d-i installation manual bits for arm64 and ppc64el

[Samuel Thibault <sthibault@debian.org>]

Hello,

One of the things that needs to get added for arm64 and ppc64el is the
installation manual bits. For now I have just commited the basics, so
you can

$ debcheckout installation-guide
$ cd installation-guide/build
$ ./buildone arm64 en pdf
$ ./buildone ppc64el en pdf

to get it built. What porters need to do is to add information specific
to their arch.

For arm64
=========

For now, arm64 is just like armel and armhf, I guess they won't differ
so much. At least these files will however probably have to be updated
to document some board-specific details:

- en/hardware/supported/arm.xml
- en/hardware/hardware-supported.xml
- en/install-methods/download/arm.xml
- en/preparing/bios-setup/arm.xml
- en/boot-installer/arm.xml
- en/using-d-i/modules/arm/flash-kernel-installer.xml

It's probably useful to also look around at paragraphs marked with
arch="arm"

For ppc64el
===========

For now, ppc64el is just like powerpc, I guess it may be useful to
distinguish them so as to drop the documentation for elder hardware?
en/hardware/hardware-supported.xml will have to be updated. At least
these files will probably have to be updated:

- en/hardware/supported/powerpc.xml
- en/hardware/hardware-supported.xml
- en/install-methods/floppy/powerpc.xml
- en/install-methods/usb-setup/powerpc.xml
- en/preparing/bios-setup/powerpc.xml
- en/boot-installer/powerpc.xml
- en/using-d-i/modules/powerpc/yaboot-installer.xml
- en/using-d-i/modules/powerpc/quik-installer.xml

It's probably useful to also look around at paragraphs marked with
arch="ppc64el"

Samuel