fixed capitalisation of LiveScript in readme
switched to pmatrix for vector equations
added equations of lines question

I’ve added the first of vrn20’s questions; specifically:

> Find the equation of the line that passes through the points ... and ....

This commit also adds the appropriate unit tests and config files. The rest of the questions will be added as a series of new commits.
including a helper function necessary for previous commit
Tidied up some edge cases for makeLinesEq
Merge pull request #20 from alexwlchan/master

Minor changes, and the first of the new functions