dracut.conf.5.asc: document how to config --no-compress in the config

Fixes: https://github.com/dracutdevs/dracut/issues/824

dracut.conf.5.asc

@@ -80,12 +80,13 @@ Configuration files must have the extension .conf; other extensions are ignored.
     Specify additional files to include in the initramfs, separated by spaces,
     if they exist.
 
-*compress=*"__{bzip2|lzma|xz|gzip|lzo|lz4|zstd|<compressor [args ...]>}__"::
+*compress=*"__{cat|bzip2|lzma|xz|gzip|lzo|lz4|zstd|<compressor [args ...]>}__"::
     Compress the generated initramfs using the passed compression program. If
     you pass it just the name of a compression program, it will call that
     program with known-working arguments. If you pass arguments, it will be called
     with exactly those arguments. Depending on what you pass, this may result in
     an initramfs that the kernel cannot decompress.
+    To disable compression, use "cat".
 
 *do_strip=*"__{yes|no}__"::
     Strip binaries in the initramfs (default=yes)