Variables are not expanded correctly in code blocks

[ptxmac]

I looks like rendering happens before template expansion, this can result in variables not being expanded if the renderer decides to change the code block for styling.

Here's a minimal example to illustrate it:

# Template Variable Demo

Enter a name:

```action:userInput variable=name
e.g. World
```

Hello, ${name}!

This works:

```
echo ${name}
```

This fails:

```bash
xxxxxxxxxxxxxxxxxxx ${name}
```

With a main file that does the bare minmum this fails when called like this:

echo "MyValue" | go run .

My guess is that the renderer adds colors to the bash syntax which then means we can no longer search for ${name}

The template expansion should be done before styling is applied