[initramfs] Document settings

- Move the README text into the config file
 - Document the *kernel* setting

src/modules/initramfs/README.md

@@ -1,12 +0,0 @@
-## initramfs module
-
-This module is specific to Debian based distros. Post installation on Debian
-the initramfs needs to be updated so as to not interrupt the boot process
-with a error about fsck.ext4 not being found.
-
-## Debian specific notes
-
-If you're using live-build to build your ISO and setup the runtime env
-make sure that you purge the live-\* packages on the target system
-before running this module, since live-config dpkg-diverts update-initramfs
-and can cause all sorts of fun issues.

src/modules/initramfs/initramfs.conf

@@ -0,0 +1,29 @@
+## initramfs module
+#
+# This module is specific to Debian based distros. Post installation on Debian
+# the initramfs needs to be updated so as to not interrupt the boot process
+# with a error about fsck.ext4 not being found.
+#
+## Debian specific notes
+#
+# If you're using live-build to build your ISO and setup the runtime env
+# make sure that you purge the live-\* packages on the target system
+# before running this module, since live-config dpkg-diverts update-initramfs
+# and can cause all sorts of fun issues.
+---
+# There is only one configuration item for this module,
+# the kernel to be loaded. This can have the following
+# values:
+#  - empty or unset, interpreted as "all"
+#  - the literal string "$uname" (without quotes, with dollar),
+#    which will use the output of `uname -r` to determine the
+#    running kernel, and use that.
+#  - any other string.
+#
+# Whatever is set, that string is passed as *version* argument to the
+# `-k` option of *update-initramfs*.
+#
+# The default is empty/unset, leading to the behavior from Calamares
+# 3.2.9 and earlier which passed "all" as version.
+
+# kernel: all