Website: update start flow images (#21503)

Changes:
- Reduced the file size of the images in the /start flow 
- Updated the "What did you think?" step of the form to display a cloud
city image.

website/views/pages/start.ejs

@@ -753,7 +753,7 @@
         </ajax-form>
       </div>
     </div>
-    <div purpose="form-image" :class="currentStep === 'start' ? 'stage-one' : currentStep === 'thanks-for-checking-out-fleet' ? 'cloud-city' : ['2 - Aware'].includes(psychologicalStage) ? 'stage-two' : ['3 - Intrigued'].includes(psychologicalStage) ? 'stage-three' : ['4 - Has use case'].includes(psychologicalStage) ? 'stage-four' : ['5 - Personally confident'].includes(psychologicalStage) ? 'stage-five' : ['6 - Has team buy-in'].includes(psychologicalStage) ? 'stage-six' : 'd-none w-0'">
+    <div purpose="form-image" :class="currentStep === 'start' ? 'stage-one' : ['thanks-for-checking-out-fleet', 'what-did-you-think'].includes(currentStep) ? 'cloud-city' : ['2 - Aware'].includes(psychologicalStage) ? 'stage-two' : ['3 - Intrigued'].includes(psychologicalStage) ? 'stage-three' : ['4 - Has use case'].includes(psychologicalStage) ? 'stage-four' : ['5 - Personally confident'].includes(psychologicalStage) ? 'stage-five' : ['6 - Has team buy-in'].includes(psychologicalStage) ? 'stage-six' : 'd-none w-0'">
     </div>
   </div>
 </div>