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

@@ -39,26 +39,39 @@ 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 |
++----------------+-----------------------+-------------------------------------+
+| Parabola       | Trisquel 10 (nabia)   | debootstrap, trisquel-keyring       |
++----------------+-----------------------+-------------------------------------+
+| Trisquel >= 10 | Trisquel 10 (nabia)   | debootstrap, trisquel-keyring       |
++----------------+-----------------------+-------------------------------------+
+
+Once you have a chroot, you can either configure it and chroot inside
+or convert it to run inside container engines like LXC, LXD, Docker
+(with debuerreotype if your distribution has a package for it), etc.
+
+It is also possible to install Trisquel 10 (nabia) or PureOS in a
+virtual machine. Note that PureOS doesn't sign its releases so we
+copied the official PureOS checksums found in several subdirectories
+in https://downloads.puri.sm/byzantium in
 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
+PureOS also has docker images on Docker Hub, and it also [has one for
-  for PureOS byzantium](https://hub.docker.com/r/pureos/byzantium). On
+PureOS byzantium](https://hub.docker.com/r/pureos/byzantium). On
-  Docker Hub, The PureOS images made by Puri.sm are the only images
+Docker Hub, The PureOS images made by Puri.sm are the only images that
-  that follow the [Free Distro
+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