mkinitfs: add page (#16109)

* mkinitfs: add page

* mkinitfs: config => configuration

Co-authored-by: Wiktor Perskawiec <git@spageektti.cc>

---------

Co-authored-by: Wiktor Perskawiec <git@spageektti.cc>

pages/linux/mkinitfs.md

@@ -0,0 +1,24 @@
+# mkinitfs
+
+> Generate an initramfs on Alpine Linux.
+> More information: <https://manned.org/mkinitfs>.
+
+- Generate an initramfs with the features specified in `/etc/mkinitfs/mkinitfs.conf`:
+
+`mkinitfs`
+
+- Use a different configuration file:
+
+`mkinitfs -c {{path/to/config}}`
+
+- Compress the initramfs using the specified compression algorithm (default: gzip):
+
+`mkinitfs -c {{gzip|xz|zstd|lz4|none}}`
+
+- List files that will be included in the initramfs image:
+
+`mkinitfs -l`
+
+- List all available features:
+
+`mkinitfs -L`