GitLab

Also added a reset.css to start fresh.

A "makefile" to generate chapter 3 in the "output" folder (Uses Python Markdown in the command-line)

`assets` folder to host static files

`templates` folder for HTML headers and footers.

Added 4 spaces to lines of code to make code blocks with markdown
extension.

repository.

publication.

All Markdown files are now located in the `source` folder.
The structure then is unchanged.

The sample codes are now located in the `sample_codes` folder.