Stage 10: HTML code editor and syntax highlighting

SimplyHTML focuses on creation and manipulation of text documents. The fact that the documents are stored as HTML files along with cascading style sheets (CSS) was hidden from the user interface of SimplyHTML intentionally. The autor should not be forced to know or work with HTML code to write a text document.

On the other hand, for an experienced user being familiar with HTML it sometimes is quicker to manipulate a certain portion of HTML directly instead of having to wade through GUI elements. For this reason this stage of SimplyHTML implements a way to work on the HTML representation of any given text document.

The following parts are covered in this stage:

- HTML code editor: a simple approach
- how to add syntax highlighting
- how to integrate the new component