Minor fixes

[skhiggins]

• Separate Style and Packages sections, as in R Guide
• Randomization: still appears to suggest wrong package (randomizelabel instead of stochatreat)
• Randomization: First bullet point formatting should be identical to that of the R Guide (for example, the line of code should be on its own line)
• Randomization: in one place it refers to random.seed but in another to numpy.random.seed
• Graphing: why are we recommending to save as svg rather than eps? We should recommend eps (which is more standard I think) and include the sub-bullet point about my crop_eps function as in the R Guide
• Misc: has typos