Doc: Template: Add CSS rules for bordered images

9f45d2ab added a documentation macro for bordered images
- Add the corresponding CSS rules to apply a drop shadow
for such images.

Change-Id: I18c4fbd7498db7b9391f33e568219e67b329e618
Reviewed-by: Venugopal Shivashankar <Venugopal.Shivashankar@qt.io>

doc/global/template/style/offline.css

@@ -18,8 +18,12 @@ img {
     height: auto;
 }
 
-.content {
+.content .border img {
+    box-shadow:3px 3px 8px 3px rgba(200,200,200,0.5)
+}
 
+.content .border .player {
+    box-shadow:3px 3px 8px 3px rgba(200,200,200,0.5)
 }
 
 .content .indexboxcont li {

doc/global/template/style/online.css

@@ -1280,6 +1280,12 @@ li a.active {
   margin-top:0.75em;
   max-width:100%
 }
+.context .border img {
+   box-shadow:3px 3px 8px 3px rgba(200,200,200,0.5)
+ }
+.context .border .player {
+   box-shadow:3px 3px 8px 3px rgba(200,200,200,0.5)
+ }
 .context table {
   vertical-align:initial
 }