fix(ui/case-study): downscale images and fix image source

sketch_map_tool/templates/case-study-timor-leste.html

@@ -13,7 +13,7 @@
   <h1>{{ _('Participatory Mapping in Timor Leste') }}</h1>
   <figure>
     <img src="{{ url_for("static",
-    filename="assets/images/case-study-timor-leste/banner.png") }}" alt="{{
+    filename="assets/images/case-study-timor-leste/banner.jpg") }}" alt="{{
     _('') }}">
     <figcaption>{{ _('') }}</figcaption>
   </figure>
@@ -88,7 +88,7 @@ <h2>{{ _('How was the Sketch Mapping organized?') }}</h2>
   </p>
   <figure>
     <img src="{{ url_for("static",
-    filename="assets/images/case-study-timor-leste/sketch-map.png") }}">
+    filename="assets/images/case-study-timor-leste/sketch-map.jpg") }}">
     <figcaption>
       {{ _('This Sketch Map shows the result of community mappers marking
       historic flood areas in orange. © Red Cross Red Crescent Climate Centre
@@ -112,7 +112,7 @@ <h2>{{ _('Results and Impact') }}</h2>
   </p>
   <figure>
     <img src="{{ url_for("static",
-    filename="assets/images/case-study-timor-leste/community-map.png") }}">
+    filename="assets/images/case-study-timor-leste/community-map.jpg") }}">
     <figcaption>
       {{ _(' This Community map shows the results of the different mapping
       activities conducted in the area including the historical flood areas
@@ -147,7 +147,7 @@ <h2>{{ _('Lessons learnt') }}</h2>
   </ol>
   <figure>
     <img src="{{ url_for("static",
-    filename="assets/images/case-study-timor-leste/community-meeting.png") }}">
+    filename="assets/images/case-study-timor-leste/community-meeting.jpg") }}">
     <figcaption>
       {{ _(' Community meeting in the Laclo valley to capture community
       knowledge of floods, impacts, and capacities. © Red Cross Red Crescent