add paragraph explaining mentor usage

Author: androolloyd

app/dashboard/templates/dashboard/sponsors.html

@@ -324,19 +324,20 @@
                 </template>
                 <manage-mentors :org_name="userOrg.org_name" :hackathon_id="hackathonObj.id" inline-template>
                   <div class="offset-3 col-6">
-                      <div class="from-group mb-3 mt-4">
-                        <label class="font-weight-semibold" for="org-mentors">Bounty Mentors (Optional) <small>Add Gitcoin/Github Usernames</small></label>
-                        <div class="form__select2 g-multiselect">
-                          <select id="org-mentors" class="mentor-users" multiple="multiple" aria-describedby="profilesHelp">
-                            {% for profile in default_mentors %}
-                            <option selected="selected"  value="{{ profile.id }}">{{ profile }}</option>
-                            {% endfor %}
-                          </select>
-                        </div>
-                      </div>
-                      <div class="form-group mb-3 mt-4">
-                        <b-button @click="updateBountyMentors();">Update Mentors</b-button>
+                    <p>Set default mentors for bounties below. Mentors will be added to hackathon chat channels that you sponsor.</p>
+                    <div class="from-group mb-3 mt-4">
+                      <label class="font-weight-semibold" for="org-mentors">Bounty Mentors (Optional) <small>Add Gitcoin/Github Usernames</small></label>
+                      <div class="form__select2 g-multiselect">
+                        <select id="org-mentors" class="mentor-users" multiple="multiple" aria-describedby="profilesHelp">
+                          {% for profile in default_mentors %}
+                          <option selected="selected"  value="{{ profile.id }}">{{ profile }}</option>
+                          {% endfor %}
+                        </select>
                       </div>
+                    </div>
+                    <div class="form-group mb-3 mt-4">
+                      <b-button class="btn btn-gc-blue"@click="updateBountyMentors();">Update Mentors</b-button>
+                    </div>
                   </div>
                 </manage-mentors>
               </b-tab>