npm install editor.md

<link rel="stylesheet" href="editormd/css/editormd.css" />

<script src="js/jquery.min.js"></script>
<script src="editormd/editormd.min.js"></script>

<link rel="stylesheet" href="editormd/css/editormd.css" />
<div id="test-editor">
<textarea style="display:none;" class="content-markdown" name="content-markdown"></textarea>
</div>
<script src="js/jquery.min.js"></script>
<script src="editormd/editormd.min.js"></script>
<script type="text/javascript">
    $(function() {
      var editor = editormd("test-editor", {
        width  : "100%",            //宽度，不填为100%
        height : "500px",           //高度，不填为100%
        theme : "dark",             //主题,不填为默认主题
        path   : "editormd/lib/",   //editor.md插件的lib目录地址
        saveHTMLToTextarea : true, // 保存 HTML 到 Textarea
        toolbarAutoFixed:true,      //工具栏自动固定定位的开启与禁用
      });
    });
</script>

$(function() {
    var editor = editormd("test-editor", {
        width  : "100%",            //宽度，不填为100%
        height : "500px",           //高度，不填为100%
        theme : "dark",             //主题,不填为默认主题
        path   : "editormd/lib/",   //editor.md插件的lib目录地址
        saveHTMLToTextarea : true, // 保存 HTML 到 Textarea
        toolbarAutoFixed:true,      //工具栏自动固定定位的开启与禁用
        imageUpload : true,         //运行本地上传
        imageFormats : ["jpg", "jpeg", "gif", "png", "bmp", "webp"],    //允许上传的文件格式
        imageUploadURL : "/index.php?r=markdown/upload"                 //上传的后台服务器路径
    });
});

Yii::$app->response->format = Response::FORMAT_JSON;
$upload = \Intervention\Image\ImageManagerStatic::make($_FILES['editormd-image-file']['tmp_name'])->save('upload/upload.jpg');//file为上传表单的name名
if ($upload) {
    return [
        'success' => 1,
        'message' => '上传成功',
        'url' => 'upload/upload.jpg'
    ];
} else {
    return [
        'success' => 0,
        'message' => '上传失败',
    ];
}