Merge bitcoin/bitcoin#22317: doc: Highlight DNS requests part in tor.md

86a4a15bdc Highlight DNS request part (Prayank)

Pull request description:

  _What?_

  Highlight DNS requests part in Proxy section

  _Why?_

  1. DNS requests are very important while considering privacy
  2. Lot of users might skip reading it because of the way it is mixed with everything else in the doc right now
  3. I have seen lot of users ignoring DNS requests or unaware of such things while using privacy tools

  _How?_

  Initially I had tried keeping these lines separate from code block but [Jonatack didn't agree with the changes](https://github.com/bitcoin/bitcoin/pull/21157#discussion_r618177116). Harding suggested using [bold/italic in `<pre></pre>`](https://github.com/bitcoin/bitcoin/pull/21157#discussion_r644364143). I have used the suggestions from previous PR and added `---`

  This is a part of alternative described in https://github.com/bitcoin/bitcoin/pull/22316

ACKs for top commit:
  jonatack:
    ACK 86a4a15bdc
  Rspigler:
    ACK 86a4a15bdc
  achow101:
    ACK 86a4a15bdc
  RiccardoMasutti:
    ACK 86a4a15
  lsilva01:
    ACK 86a4a15bdc
  kristapsk:
    ACK 86a4a15bdc
  theStack:
    ACK 86a4a15bdc

Tree-SHA512: a4fe0e8c08df330e5ca78ce19ce74be7034c653f4374469d928908847a6debf385283e3a6da66de600566c7bab6290ccd35df26864aef94cbb3f294123391437

doc/tor.md

@@ -40,9 +40,11 @@ outgoing connections, but more is possible.
     -onion=ip:port  Set the proxy server to use for Tor onion services. You do not
                     need to set this if it's the same as -proxy. You can use -onion=0
                     to explicitly disable access to onion services.
+                    ------------------------------------------------------------------
                     Note: Only the -proxy option sets the proxy for DNS requests;
                     with -onion they will not route over Tor, so use -proxy if you
                     have privacy concerns.
+                    ------------------------------------------------------------------
 
     -listen         When using -proxy, listening is disabled by default. If you want
                     to manually configure an onion service (see section 3), you'll