treewide: fix typos and other minor issues

docs/rspamd-tuning.rst

@@ -94,7 +94,7 @@ With an nginx reverse-proxy
 
 If you have a secured nginx reverse proxy set on the host, you can use it to expose the socket.
 **Keep in mind the UI is unsecured by default, you need to setup an authentication scheme**, for
-exemple with `basic auth <https://docs.nginx.com/nginx/admin-guide/security-controls/configuring-http-basic-authentication/>`_:
+example with `basic auth <https://docs.nginx.com/nginx/admin-guide/security-controls/configuring-http-basic-authentication/>`_:
 
 .. code:: nix