build instructions: Mention exact package names for debootstrap.

We need to install the keyring packages to make sure that the
signatures are checked. So a table was created for that and also to
enable to add more distributions in it (like Guix) later on.

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
Acked-by: Adrien 'neox' Bourmault <neox@gnu.org>

site/docs/build/index.md

@@ -39,31 +39,44 @@ And these cannot build GNU Boot yet:
   building Coreboot for certain computers.
 
 If you don't use PureOS 10 (byzantium) or Trisquel 10 (nabia), there
-are many ways to run them on top of other GNU/Linux distributions:
+are many ways to run them on top of other GNU/Linux distributions.
 
-* A Trisquel 10 chroot can be created with the debootstrap and
+If you run Parabola, Trisquel 10 (nabia) or Trisquel 11 (aramo), you
-  trisquel-keyring packages under the Trisquel or Parabola
+can use debootstrap to create a chroot of Trisquel 10 (nabia) or
-  distributions. Once this is done you can either configure it and
+PureOS 10 (byzantium). Here are the packages you need to install
-  chroot inside or convert it to run inside container engines like
+depending on your distribution:
-  LXC, LXD, Docker (with debuerreotype), etc.
 
-* It is possible to install Trisquel 10 (nabia) or PureOS in a virtual
++----------------+-----------------------+-------------------------------------+
-  machine. Note that PureOS doesn't sign its releases so we copied the
+| Host distro    | Chroot distro         | Required packages                   |
-  official PureOS checksums found in several subdirectories in
++----------------+-----------------------+-------------------------------------+
-  https://downloads.puri.sm/byzantium in
+| Parabola       | PureOS 10 (byzantium) | debootstrap, pureos-archive-keyring |
-  resources/distros/pureos/20230614/ in the GNU Boot repository. The
++----------------+-----------------------+-------------------------------------+
-  commits of GNU Boot are usually signed by its maintainers, so it's
+| Parabola       | Trisquel 10 (nabia)   | debootstrap, trisquel-keyring       |
-  also possible to have a full chain of trust.
++----------------+-----------------------+-------------------------------------+
+| Trisquel >= 10 | Trisquel 10 (nabia)   | debootstrap, trisquel-keyring       |
++----------------+-----------------------+-------------------------------------+
 
-* PureOS also has docker images on Docker Hub, and it also [has one
+Once you have a chroot, you can either configure it and chroot inside
-  for PureOS byzantium](https://hub.docker.com/r/pureos/byzantium). On
+or convert it to run inside container engines like LXC, LXD, Docker
-  Docker Hub, The PureOS images made by Puri.sm are the only images
+(with debuerreotype if your distribution has a package for it), etc.
-  that follow the [Free Distro
+
-  Guidelines](https://www.gnu.org/distros/). Also note that it is not
+It is also possible to install Trisquel 10 (nabia) or PureOS in a
-  possible to easily check the integrity of images coming from docker
+virtual machine. Note that PureOS doesn't sign its releases so we
-  hub so by using them you blindly trust Docker Hub. The only way to
+copied the official PureOS checksums found in several subdirectories
-  check the images is to create your own image and compare it with the
+in https://downloads.puri.sm/byzantium in
-  one hosted on docker hub.
+resources/distros/pureos/20230614/ in the GNU Boot repository. The
+commits of GNU Boot are usually signed by its maintainers, so it's
+also possible to have a full chain of trust.
+
+PureOS also has docker images on Docker Hub, and it also [has one for
+PureOS byzantium](https://hub.docker.com/r/pureos/byzantium). On
+Docker Hub, The PureOS images made by Puri.sm are the only images that
+follow the [Free Distro
+Guidelines](https://www.gnu.org/distros/). Also note that it is not
+possible to easily check the integrity of images coming from docker
+hub so by using them you blindly trust Docker Hub. The only way to
+check the images is to create your own image and compare it with the
+one hosted on docker hub.
 
 Git
 ===