Cover more of the features in the description.

docs/pv.1

@@ -1,7 +1,7 @@
 .TH PV 1 2025-10-17 pv-1.9.44 "User Commands"
 .\"
 .SH NAME
-pv \- monitor the progress of data through a pipe
+pv \- monitor and manage the progress of data through a pipe
 .\"
 .SH SYNOPSIS
 .B pv
@@ -16,11 +16,15 @@ pv \- monitor the progress of data through a pipe
 Show the progress of data through a pipeline by giving information such as
 time elapsed, percentage completed (with progress bar), current throughput
 rate, total data transferred, and ETA.
+The data flow rate, error handling strategy, buffer size, and cache
+interaction can all be adjusted.
 .PP
 Each \fIFILE\fR is copied to standard output.
 With no \fIFILE\fR, or when \fIFILE\fR is \*(lq-\*(rq, standard input is
 read.
-This is the same behaviour as \fBcat\fR(1).
+.PP
+In \*(lq\fB\-\-watchfd\fR\*(rq mode, inspect another process and show its
+progress through the files it has open.
 .\"
 .SH OPTIONS
 .\"

docs/pv.1.md

@@ -1,6 +1,6 @@
 # NAME
 
-pv - monitor the progress of data through a pipe
+pv - monitor and manage the progress of data through a pipe
 
 # SYNOPSIS
 
@@ -15,11 +15,15 @@ pv - monitor the progress of data through a pipe
 
 Show the progress of data through a pipeline by giving information such
 as time elapsed, percentage completed (with progress bar), current
-throughput rate, total data transferred, and ETA.
+throughput rate, total data transferred, and ETA. The data flow rate,
+error handling strategy, buffer size, and cache interaction can all be
+adjusted.
 
 Each *FILE* is copied to standard output. With no *FILE*, or when *FILE*
-is "-", standard input is read. This is the same behaviour as
-**cat**(1).
+is "-", standard input is read.
+
+In "**\--watchfd**" mode, inspect another process and show its progress
+through the files it has open.
 
 # OPTIONS