…empty.

This change essentially performs the same operation as the existing code which processes the 'data-output'
atrribute values, but in an automatic fashion.

When the 'data-filter' attribute is found in the <pre> element with a non-empty value, visit each line of the
<code> content. If the line starts with the value found in the 'data-prompt' attribute, treat it as a command
and wrap the text in <span class="command-line-command">. Otherwise, treat the line as command output and strip
off any data-user, data-host, or data-prompt attributes, just like the code which performs filter based on line
numbers and ranges.

…empty.

This change essentially performs the same operation as the existing code which processes the 'data-output'
atrribute values, but in an automatic fashion.

When the 'data-filter' attribute is found in the <pre> element with a non-empty value, visit each line of the
<code> content. If the line starts with the value found in the 'data-prompt' attribute, treat it as a command
and wrap the text in <span class="command-line-command">. Otherwise, treat the line as command output and strip
off any data-user, data-host, or data-prompt attributes, just like the code which performs filter based on line
numbers and ranges.

…-pages