Create welcome.md
What the course is and is not.
How to follow the course.
Typos.
Link to software carpentry as a way to meet the prerequisites.
Indicate about tags that can be used to switch to tutor versions of the code.
Create 01scaffold.md
Explain a few things about the boilerplate.
Explain why we're not giving clear formal syntax definitions.
Explain coding convention.
Describe the header file
Update 01scaffold.md
Remove unncessary intimidation.
Update 01scaffold.md
Explain tests.
Update 01scaffold.md
Note on constructors and on std::
Format quote as code
Format quote as code
Explain member variable and private.