Support for initcpio (#31)

* Add initcpio hook and install script

* Make PIN optional

* Add README for initcpio

* Fix PKGBUILD, add install of initcpio

* Fix README for initcpio

initcpio/install/fido2luks

@@ -0,0 +1,31 @@
+#!/bin/bash
+
+build() {
+    local mod
+
+    add_module dm-crypt
+    add_module dm-integrity
+    if [[ $CRYPTO_MODULES ]]; then
+        for mod in $CRYPTO_MODULES; do
+            add_module "$mod"
+        done
+    else
+        add_all_modules /crypto/
+    fi
+
+    add_binary fido2luks
+    add_binary dmsetup
+    add_file /usr/lib/udev/rules.d/10-dm.rules
+    add_file /usr/lib/udev/rules.d/13-dm-disk.rules
+    add_file /usr/lib/udev/rules.d/95-dm-notify.rules
+    add_file /usr/lib/initcpio/udev/11-dm-initramfs.rules /usr/lib/udev/rules.d/11-dm-initramfs.rules
+    add_file /etc/fido2luks.conf /etc/fido2luks.conf
+
+    add_runscript
+}
+
+help() {
+    cat <<HELPEOF
+This hook allows to decrypt LUKS2 partition using FIDO2 compatible authenticator
+HELPEOF
+}