Update Highlight.js

[doamatto]

What do you want added to PrivacySpy?
When running gulp to build the site, I get the following warning:

Version 9 of Highlight.js has reached EOL and is no longer supported.
Please upgrade or ask whatever dependency you are using to upgrade.
https://github.com/highlightjs/highlight.js/issues/2877

It seems the source is from the seemingly abandoned helpers/handlebars-helpers package we use. The easiest option is to try and maintain it ourselves or find someone who already is doing so. A harder option is to find an alternative to replace it at build time.
This issues should probably have the assign expanded to both @milesmcc and @ibarakaiev since this is a pretty big thing based on the realistic resolution options.

Have you considered implementing this addition yourself and submitting a pull request?
If we come to a conclusion as to handle this, I can gladly try to impliment it myself.

[privacyspy-bot]

Thanks for submitting this issue. @milesmcc has been assigned to determine next steps.

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