Feature Request: Add Captions to Images

#### Description
The current version of YFM allows users to add images with `alt-text` and `title` props. To enhance image context and readability, i propose utilizing the `figcaption` HTML tag for rendering captions.
To enable the display of the caption you need to add the `{ caption }` as attribute, the default value is equal to the title, but it can also be passed in the attribute

#### Example Syntax
```markdown
![Alt text](_images/image.png "Caption text" =100x100){ caption }
```
In this example, the "Caption text" should be rendered within a figcaption tag below the image.

#### Example HTML Output
The resulting HTML should look like this:
```html

Caption text

```

DOCSTOOLS-3428