added README
added the notebook
Merge https://github.com/numerical-mooc/assignment-bank

Conflicts:
	LogisticLeapFrog/LogisticLeapFrog.ipynb
Merge pull request #6 from SigurdAngenent/master

leap frog for logistic equation
Apply style to "phugoid variations"

And tweak figure to fit text width
Ignore checkpoints
Add author and license note
Apply style to notebook
Add style to predator-prey notebook
Add style to predator-prey
Merge pull request #2 from numerical-mooc/master

Updating my fork