made mobile Editor mode menu more easier to read

src/client/js/components/PageEditor/EditorNavbarBottom.jsx

@@ -115,7 +115,7 @@ const EditorNavbarBottom = (props) => {
         <Collapse isOpen={isExpanded}>
           <div className="px-2"> {/* set padding for border-top */}
             <div className={`navbar navbar-expand border-top px-0 ${additionalClasses.join(' ')}`}>
-              <form className="form-inline ml-auto">
+              <form className="form-inline ml-sm-auto">
                 <OptionsSelector />
               </form>
             </div>

src/client/js/components/PageEditor/OptionsSelector.jsx

@@ -247,9 +247,9 @@ class OptionsSelector extends React.Component {
   render() {
     return (
       <div className="d-flex flex-row">
-        <span className="ml-3">{this.renderThemeSelector()}</span>
-        <span className="ml-4">{this.renderKeymapModeSelector()}</span>
-        <span className="ml-4">{this.renderConfigurationDropdown()}</span>
+        <span className="ml-sm-3">{this.renderThemeSelector()}</span>
+        <span className="ml-sm-4">{this.renderKeymapModeSelector()}</span>
+        <span className="ml-sm-4">{this.renderConfigurationDropdown()}</span>
       </div>
     );
   }