website: Wrap problematic code-blocks in `{{% raw %}}`

Code blocks containing double curley brackets, such as:

```
{{ user `boot_command_prefix` }}
```

, confuses the Jekyll markdown renderer. To fix this code-blocks
containing curly brackets need wrapped in `{{% raw %}}/{$ endraw %}}`.
For example:

{% raw %}
```
{{ user `boot_command_prefix` }}
```
{% endraw %}

Change-Id: Ia487f8cef8fcb09381cedd9e446a67425b00f3ca
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-website/+/55164
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: Bobby Bruce <bbruce@ucdavis.edu>
3 files changed