Update usage.html

Author: nofurtherinformation

docs/usage.html

@@ -247,8 +247,8 @@ <h3>Filter by Census Tract</h3>
   </osl-modal>
 
       <br />
-      <div style="width:100%;height:100vh;position:relative">
-        <osl-flex-box breakpoint="lg">
+      <div style="width:100%;height:80vh;position:relative">
+        <osl-flex-box breakpoint="lg" style="height:100%" >
           <div style="flex-basis:25%; flex-grow:0;">
             <div>
               <sp-theme>