syntax highlighting

[ghost]

markdown supports syntax highlighting:

https://spec.commonmark.org/0.28/#example-111

example:

~~~sh
#!/bin/sh
echo 'hello world'
~~~

result:

#!/bin/sh
echo 'hello world'

i see textile offers block code:

https://promptworks.com/textile/html-integration-and-escapement#block-code

but i do not see a way to highlight the code.