Add license and basic documentation

LICENSE:
Add GPL-3.0 license.

{{archiso,configs}/*,.editorconfig,.gitlab-ci.yml}:
Add SPDX license identifier.

Makefile:
Add SPDX license identifier.
Install the `run_archiso.sh` script as global executable `run_archiso`.
Use -D and -t flags to install to install files more generically (without a previous call to install the directory).

README.rst:
Add README outlining the project's scope, how to build images from the profiles and how to test.

AUTHORS.rst:
Add list of all direct contributors to the repository.

CONTRIBUTING.rst:
Add basic contribution guidelines, explaining the linter and the license in use.

Closes #7
Closes #3

6 files changed, 15 insertions, 0 deletions

diff --git a/configs/baseline/build.sh b/configs/baseline/build.sh
index 0649d4b..92d1249 100755
--- a/configs/baseline/build.sh
+++ b/configs/baseline/build.sh
@@ -1,4 +1,6 @@
 #!/usr/bin/env bash
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
 
 set -e -u
 
diff --git a/configs/baseline/isolinux/isolinux.cfg b/configs/baseline/isolinux/isolinux.cfg
index 33e8b65..e078ce3 100644
--- a/configs/baseline/isolinux/isolinux.cfg
+++ b/configs/baseline/isolinux/isolinux.cfg
@@ -1,3 +1,6 @@
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
 PATH /%INSTALL_DIR%/boot/syslinux/
 DEFAULT loadconfig
 
diff --git a/configs/baseline/mkinitcpio.conf b/configs/baseline/mkinitcpio.conf
index 279eccb..2f9a39a 100644
--- a/configs/baseline/mkinitcpio.conf
+++ b/configs/baseline/mkinitcpio.conf
@@ -1 +1,4 @@
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
 HOOKS=(base udev archiso block filesystems)
diff --git a/configs/baseline/packages.x86_64 b/configs/baseline/packages.x86_64
index d3ad7bf..14fe5f0 100644
--- a/configs/baseline/packages.x86_64
+++ b/configs/baseline/packages.x86_64
@@ -1,3 +1,5 @@
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
 base
 linux
 mkinitcpio
diff --git a/configs/baseline/pacman.conf b/configs/baseline/pacman.conf
index bbca42f..9d895e9 100644
--- a/configs/baseline/pacman.conf
+++ b/configs/baseline/pacman.conf
@@ -2,6 +2,8 @@
 # /etc/pacman.conf
 #
 # See the pacman.conf(5) manpage for option and repository directives
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
 
 #
 # GENERAL OPTIONS
diff --git a/configs/baseline/syslinux/syslinux.cfg b/configs/baseline/syslinux/syslinux.cfg
index e31bb8c..a3908da 100644
--- a/configs/baseline/syslinux/syslinux.cfg
+++ b/configs/baseline/syslinux/syslinux.cfg
@@ -1,3 +1,6 @@
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
 UI boot/syslinux/menu.c32
 MENU TITLE Arch Linux
 MENU CLEAR