alpine: Migrate rc.local bootstrap tasks to finit.conf

Finit now supports pipes and redirects in run/task stanzas.  Hence, we
can reduce rc.local to an example template.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

contrib/alpine/rc.local

@@ -1,2 +1,8 @@
 #!/bin/sh
-zcat /etc/keymap/se.bmap.gz | loadkmap
+# This script is executed once at boot, at the very end,
+# right before starting the TTYs.
+#
+# Each line is run in sequence.
+#
+# NOTE: Remeber to set the executable bit!
+#