docs(contributing): add recent semantic-release formulas

* myii/ssf-formula#150
* myii/ssf-formula#156
  - myii/ssf-formula#157
* myii/ssf-formula#160

CONTRIBUTING.rst

@@ -198,6 +198,7 @@ These formulas are already compatible with semantic-release:
 #. `nfs-formula </~https://github.com/saltstack-formulas/nfs-formula>`_
 #. `nginx-formula </~https://github.com/saltstack-formulas/nginx-formula>`_
 #. `nifi-formula </~https://github.com/saltstack-formulas/nifi-formula>`_
+#. `node-formula </~https://github.com/saltstack-formulas/node-formula>`_
 #. `ntp-formula </~https://github.com/saltstack-formulas/ntp-formula>`_
 #. `openldap-formula </~https://github.com/saltstack-formulas/openldap-formula>`_
 #. `openssh-formula </~https://github.com/saltstack-formulas/openssh-formula>`_
@@ -206,6 +207,7 @@ These formulas are already compatible with semantic-release:
 #. `php-formula </~https://github.com/saltstack-formulas/php-formula>`_
 #. `postfix-formula </~https://github.com/saltstack-formulas/postfix-formula>`_
 #. `postgres-formula </~https://github.com/saltstack-formulas/postgres-formula>`_
+#. `powerdns-formula </~https://github.com/saltstack-formulas/powerdns-formula>`_
 #. `prometheus-formula </~https://github.com/saltstack-formulas/prometheus-formula>`_
 #. `rabbitmq-formula </~https://github.com/saltstack-formulas/rabbitmq-formula>`_
 #. `redis-formula </~https://github.com/saltstack-formulas/redis-formula>`_
@@ -221,6 +223,7 @@ These formulas are already compatible with semantic-release:
 #. `telegraf-formula </~https://github.com/saltstack-formulas/telegraf-formula>`_
 #. `template-formula </~https://github.com/saltstack-formulas/template-formula>`_
 #. `timezone-formula </~https://github.com/saltstack-formulas/timezone-formula>`_
+#. `tomcat-formula </~https://github.com/saltstack-formulas/tomcat-formula>`_
 #. `ufw-formula </~https://github.com/saltstack-formulas/ufw-formula>`_
 #. `users-formula </~https://github.com/saltstack-formulas/users-formula>`_
 #. `varnish-formula </~https://github.com/saltstack-formulas/varnish-formula>`_