document --tmpdir option

dracut.8.asc

@@ -217,6 +217,12 @@ Default:
 Default:
    _/etc/dracut.conf.d_
 
+**--tmpdir** _<temporary directory>_::
+    specify temporary directory to use.
++
+Default:
+   _/var/tmp_
+
 **--sshkey** _<sshkey file>_:: ssh key file used with ssh-client module.
 
 **-l, --local**::

dracut.conf.5.asc

@@ -67,6 +67,9 @@ line are not interpreted.
 *hostonly=*"__{yes|no}__"::
     Host-Only mode: Install only what is needed for booting the local host instead of a generic host.
 
+*tmpdir=*"__<temporary directory>__"::
+    Specify temporary directory to use.
+
 [WARNING]
 ====
 If chrooted to another root other than the real root device, use --fstab and provide a valid _/etc/fstab_.