Is there any support for custom widgets for the visual editor?

E.g. I have an astro component (via rehype and remark plugins) which renders markdown of form below as photo gallery component:

---
- ![my photo1 subtitle](./my/image_url1)
- ![my photo2 subtitle](./my/image_url2)
- ![my photo3 subtitle](./my/image_url3)
---

I'd like to have a nicer Photo Gallery widget for configuring a list of images and serialize them in markdown like so. I'd like to at least have some support in the visual editor (but also ideally in the preview pane: e.g. at least make all images in image lists to have same image height)

Another example: I'm rendering markdown of form:

---

# lead heading 1
word1 word1 word1
[Link button 1](./url1)

---

# lead heading 2
word2 word2 word2
[Link button 2](./url2)

---

as two-column layout with two leads (and special styling for the link button)

In addition to editing markdown, is there support for editing HTML / JSON / YAML files (e.g. my *.astro files using some custom component elements) with some syntax highlighting?

Thanks :)