doc/kdig: update +fastopen description, add example

doc/man/kdig.1in

@@ -235,7 +235,7 @@ Show the TTL value.
 Use the TCP protocol (default is UDP for standard query and TCP for AXFR/IXFR).
 .TP
 \fB+\fP[\fBno\fP]\fBfastopen\fP
-Use TCP Fast Open (default with TCP).
+Use TCP Fast Open.
 .TP
 \fB+\fP[\fBno\fP]\fBignore\fP
 Don\(aqt use TCP automatically if a truncated reply is received.
@@ -406,6 +406,7 @@ DNS over HTTPS examples (various DoH implementations):
 $ kdig @1.1.1.1 +https example.com.
 $ kdig @193.17.47.1 +https=/doh example.com.
 $ kdig @8.8.4.4 +https +https\-get example.com.
+$ kdig @8.8.8.8 +https +tls\-hostname=dns.google +fastopen example.com.
 .ft P
 .fi
 .UNINDENT

doc/man_kdig.rst

@@ -214,7 +214,7 @@ Options
   Use the TCP protocol (default is UDP for standard query and TCP for AXFR/IXFR).
 
 **+**\ [\ **no**\ ]\ **fastopen**
-  Use TCP Fast Open (default with TCP).
+  Use TCP Fast Open.
 
 **+**\ [\ **no**\ ]\ **ignore**
   Don't use TCP automatically if a truncated reply is received.
@@ -353,6 +353,7 @@ Examples
      $ kdig @1.1.1.1 +https example.com.
      $ kdig @193.17.47.1 +https=/doh example.com.
      $ kdig @8.8.4.4 +https +https-get example.com.
+     $ kdig @8.8.8.8 +https +tls-hostname=dns.google +fastopen example.com.
 
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