I am trying create an update route but whenever I try to update the content I can only update title and description & markdown but not sanitized html. How Can I udpate the sanitized html while I edit.
Here is my article.js model.

```js
const mongoose = require('mongoose');
const marked = require('marked');
const slugify = require('slugify');
const createDomPurify = require('dompurify');
const { JSDOM } = require('jsdom');
const dompurify = createDomPurify(new JSDOM().window);

const articleSchema = new mongoose.Schema({
  title: {
    type: String,
    required: true,
  },
  description: {
    type: String,
  },
  markdown: {
    type: String,
    required: true,
  },
  createdAt: {
    type: Date,
    default: Date.now,
  },
  slug: {
    type: String,
    required: true,
    unique: true,
  },
  sanitizedHtml: {
    type: String,
    required: true,
  },
});

articleSchema.pre('validate', function (next) {
  if (this.title) {
    this.slug = slugify(this.title, { lower: true, strict: true });
  }

  if (this.markdown) {
    this.sanitizedHtml = dompurify.sanitize(marked.parse(this.markdown));
  }

  next();
});

module.exports = mongoose.model('Article', articleSchema);

```

Here is my put route :

```js
router.put('/:id', async (req, res) => {
  const { id } = req.params;
  const article = Article.findById(id);
  const newArticle = {
    title: req.body.title,
    description: req.body.description,
    markdown: req.body.markdown,
  };
  const updatedArticle = await Article.findByIdAndUpdate(id, newArticle);
  await updatedArticle.save();
  res.redirect(`/articles/${article.slug}`);
});

```