documentation: add zram recompression documentation

mainline inclusion
from mainline-v6.2-rc1
commit 443dd798
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I7TWVA
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=443dd798062c1549e790539e572cbda4b7a8df30

-------------------------------------------

Document user-space visible device attributes that are enabled by
ZRAM_MULTI_COMP.

Link: https://lkml.kernel.org/r/20221109115047.2921851-12-senozhatsky@chromium.org


Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Alexey Romanov <avromanov@sberdevices.ru>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Conflicts:
	Documentation/admin-guide/blockdev/zram.rst

Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>