Added the following code to _custom.scss to add a horizontal scrollbar (issue #14) to the code sections:

.highlight {
    overflow-x: auto;

Also updated the description for the use of the –incremental option to the page on Jekyll -> Speed. In the Jekyll release 3.7 this option is very usefull to keep the development build of Jekyll down to a minimum. My own site needs only 1.5 seconds to rebuild a page that I am working on. This down from 70 seconds with Jekyll 3.6.