update man template
@@ -21,8 +21,12 @@ Optional key-value pairs to be included in the request.
.IP
\fBkey=value\fR to add a JSON field (\fB\-\-json\fR) or form field (\fB\-\-form\fR)
.IP
+\fBkey=@value\fR to add a JSON field (\fB\-\-json\fR) or form field (\fB\-\-form\fR) from a file.
+.IP
\fBkey:=value\fR to add a complex JSON value (e.g. `numbers:=[1,2,3]`)
.IP
+\fBkey:=@value\fR to add a complex JSON value (e.g. `numbers:=@data.json`) from a file.
+.IP
\fBkey@filename\fR to upload a file from filename (with \fB\-\-form\fR)
.IP
\fBheader:value\fR to add a header
