Adding make lesson

Giant pull request for cohort 09's work on Make lesson
This line is the output of the previous one. Please replace

    ~~~
    $ ls -t *.dat *.svg
    summary-1.dat figure-1.svg
    ~~~
    {class="in"}

with

    ~~~
    $ ls -t *.dat *.svg
    ~~~
    {class="in"}
    ~~~
    summary-1.dat figure-1.svg
    ~~~
    {class="out"}

**Please also make this correction in all the others code samples.**