add Ts and Cs to checkbox for school profile/onboarding

app/views/schools/on_boarding/profiles/onboarding.html.erb

@@ -41,6 +41,7 @@
             <li>the details you’re providing are correct</li>
             <li>you agree to manage the data you receive in line with current UK GDPR regulations</li>
             <li>you accept our <a href="/schools_privacy_policy" class="govuk-link">privacy policy</a></li>
+            <li>you accept our <a href="/terms_and_conditions" class="govuk-link">terms and conditions</a></li>
           </ul>
           </p>
         <% end %>