fix: Ctrl-Space autocomplete not working

packages/app/src/components/Admin/CustomHeaderEditor.jsx

@@ -7,6 +7,8 @@ require('codemirror/addon/hint/show-hint');
 require('codemirror/addon/edit/matchbrackets');
 require('codemirror/addon/edit/closebrackets');
 require('codemirror/mode/htmlmixed/htmlmixed');
+require('codemirror/addon/hint/html-hint');
+require('codemirror/addon/edit/closetag');
 require('~/client/util/codemirror/autorefresh.ext');
 
 require('jquery-ui/ui/widgets/resizable');
@@ -22,6 +24,7 @@ export default class CustomHeaderEditor extends React.Component {
         detach
         options={{
           mode: 'htmlmixed',
+          autoCloseTags: true,
           lineNumbers: true,
           tabSize: 2,
           indentUnit: 2,

packages/app/src/styles/_vendor.scss

@@ -18,6 +18,7 @@
 
 // import CodeMirror styles
 @import '~codemirror/lib/codemirror.css';
+@import '~codemirror/addon/hint/show-hint.css';
 @import '~codemirror/theme/elegant.css';
 @import '~codemirror/theme/eclipse.css';