blk-mq: ABI/sysfs-block: fix docs build warnings

Clean up the async_depth documentation:
- insert blank lines before and after lists where needed
- convert verb tense in a few places
- make lines fit within 80 characters

Documentation/ABI/stable/sysfs-block:612: ERROR: Unexpected indentation. [docutils]
Documentation/ABI/stable/sysfs-block:612: ERROR: Unexpected indentation. [docutils]
Documentation/ABI/stable/sysfs-block:612: ERROR: Unexpected indentation. [docutils]

Fixes: 2c04718 ("blk-mq: add documentation for new queue attribute async_dpeth")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: rddunlap

Documentation/ABI/stable/sysfs-block

@@ -613,34 +613,45 @@ What:		/sys/block/<disk>/queue/async_depth
 Date:		August 2025
 Contact:	linux-block@vger.kernel.org
 Description:
-		[RW] Controls how many asynchronous requests may be allocated in the
-		block layer. The value is always capped at nr_requests.
+		[RW] Controls how many asynchronous requests may be allocated
+		in the block layer. The value is always capped at nr_requests.
 
 		When no elevator is active (none):
+
 		- async_depth is always equal to nr_requests.
 
 		For bfq scheduler:
+
 		- By default, async_depth is set to 75% of nr_requests.
 		  Internal limits are then derived from this value:
+
 		  * Sync writes: limited to async_depth (≈75% of nr_requests).
-		  * Async I/O: limited to ~2/3 of async_depth (≈50% of nr_requests).
+		  * Async I/O: limited to ~2/3 of async_depth (≈50% of
+		    nr_requests).
 
 		  If a bfq_queue is weight-raised:
-		  * Sync writes: limited to ~1/2 of async_depth (≈37% of nr_requests).
-		  * Async I/O: limited to ~1/4 of async_depth (≈18% of nr_requests).
 
-		- If the user writes a custom value to async_depth, BFQ will recompute
-		  these limits proportionally based on the new value.
+		  * Sync writes: limited to ~1/2 of async_depth (≈37% of
+		    nr_requests).
+		  * Async I/O: limited to ~1/4 of async_depth (≈18% of
+		    nr_requests).
+
+		- If the user writes a custom value to async_depth, BFQ will
+		  recompute these limits proportionally based on the new value.
 
 		For Kyber:
+
 		- By default async_depth is set to 75% of nr_requests.
-		- If the user writes a custom value to async_depth, then it override the
-		  default and directly control the limit for writes and async I/O.
+		- If the user writes a custom value to async_depth, then it
+		  overrides the default and directly controls the limit for
+		  writes and async I/O.
 
 		For mq-deadline:
+
 		- By default async_depth is set to nr_requests.
-		- If the user writes a custom value to async_depth, then it override the
-		  default and directly control the limit for writes and async I/O.
+		- If the user writes a custom value to async_depth, then it
+		  overrides the default and directly controls the limit for
+		  writes and async I/O.
 
 
 What:		/sys/block/<disk>/queue/nr_zones