doc: improve fs.read documentation

PR-URL: #29270
Reviewed-By: Robert Nagy <ronagy@icloud.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

doc/api/fs.md

@@ -2735,7 +2735,7 @@ changes:
 
 Read data from the file specified by `fd`.
 
-`buffer` is the buffer that the data will be written to.
+`buffer` is the buffer that the data (read from the fd) will be written to.
 
 `offset` is the offset in the buffer to start writing at.