Fix explorer height

Author: ShukantPal

packages/webdoc-default-template/src/styles/explorer.scss

@@ -5,8 +5,8 @@
   background-color: $colorSheetSecondary;
   display: flex;
   flex-direction: column;
-  padding-bottom: 8px;
   margin: 0;
+  min-height: 100%;
   max-height: 100%;
   min-width: 291px;
 
@@ -18,6 +18,10 @@
   &__tree > *:first-child {
     margin-top: 8px;
   }
+
+  &__tree {
+    margin-bottom: 8px;
+  }
 }
 
 /* This appears outside of .explorer when its closed. */