Implement syntax highlighting in Markdown-formatted content

[carlbennett]

With Markdown, it's possible to indicate which language should be used for syntax highlighting by specifying it in the opening of the code block.

Example:
```cpp
int test = 0;
```

Perhaps it's possible to integrate syntax highlighting into the third-party library: Parsedown; we already use this third-party library to render Markdown-formatted content. This would allow contributing back to the open-source community and it would enable syntax highlighting all over the site where Markdown can be used.

[carlbennett]

This was implemented into the feature/bootstrap branch:
develop...feature/bootstrap

[carlbennett]

This has been implemented in the latest version of the code as of 4c31d5d.