Update templates/includes/authenticated.html

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>

Author: czc0407

templates/includes/authenticated.html

@@ -13,7 +13,7 @@
                         {% if user.has_membership %}
                             <a href="{% url 'users:user_membership_edit' %}">Edit your membership</a>
                         {% else %}
-                            <a href="{% url 'users:user_membership_create' %}">Join PSF Membership</a>
+                            <a href="{% url 'users:user_membership_create' %}">Join the PSF</a>
                         {% endif %}
                     {% else %}
                         <a href="{% url 'account_login' %}?next=https://psfmember.org/membership/">