clean up intro rmdhunks

[aspina7]

had commented some stuff out because erroring with the moving of props functions #32
need to fix up the examples appropratiely.

[aspina7]

instead of calling attack_rate functions to demonstrate merging, just create an example dataframe with props and cis.

conf.low = (p - qnorm(0.975) * sqrt(p * (1 - p) / N))
conf.high =( p + qnorm(0.975) * sqrt(p * (1 - p) / N))

[aspina7]

dealt with in #40