lan-only: add doc to run a DHT node

Change-Id: Ic31ab90abf0c8d498eafdf29e4d7a208dd8817c7

user/lan-only.rst

@@ -36,6 +36,14 @@ In the advanced account settings, the user can configure multiple bootstraps.
 **bootstrap.jami.net** is usually the default, **bootstrap.jami.net;your.bootstrap.tld**
 will be valid. The IP:port of another DHT node can be specified as a bootstrap.
 
+Running a bootstrap
+~~~~~~~~~~~~~~~~~~~
+
+It's possible to run a DHT node to serve as a bootstrap for Jami clients. In this case,
+the bootstrap field in the settings must be replaced by the new bootstrap.
+The documentation to run a DHT node is located in OpenDHT's wiki:
+https://github.com/savoirfairelinux/opendht/wiki/Running-a-node-with-dhtnode
+
 Local Peer Discovery
 ~~~~~~~~~~~~~~~~~~~~