Feature 208 render pr issue markdown

[d0c-s4vage]

fixes #208

Given this markdown:

This is content

```markdown {gif=true gif.cols=80 gif.rows=20}
# Render me please

| table | table |
|:------|------:|
| v1    | v1    |
```

This fenced markdown block containing the gif=true metadata is extracted and rendered into the gif below:

[d0c-s4vage]

This is a comment, testing the new workflow

Testing

[d0c-s4vage]

# Slide 1

Testing

# Slide 2

Testing 2

[github-actions[bot]]

The preview below was generated by the markdown in this comment:

[d0c-s4vage]

# Render me please

| table | table |
|:------|------:|
| v1    | v1    |

[github-actions[bot]]

The preview below was generated by the markdown in this comment: