module 4 lab Reactome - update

[risserlin]

enter and update Robin's original lab.

[risserlin]

moved exercise 2 to exercise 1
went through exercise 1 and 2 completely adjusting where necessary.
At one section it was titled "how to add pie charts" but gave instructions and screenshot for bar charts. I changed it to pie charts as stated in the title.
Also, missing steps for how to make the nodes square so that you can see the module it belongs to so I added it as a bonus exercise.
added circle attribute layout as a bonus as well.