Added maven compiler and made README clearer

[WangRyan408]

I'm not a java guy but your original README is confusing as heck. Calling IraRothPlanner directly assumes that it compiles to a binary but afaik without some special packages and stuff (which I don't see in the pom file) it'll just compile to JAR. Also not sure how the output is supposed to look, ended up getting the following using the example args:

Year=2026, age=(60,59),ira=(86276,155298),roth=(12857,23143),rmd=(0,0),income=48000,medicare=0,tax=2323,taxRate=5
Year=2027, age=(61,60),ira=(76867,138360),roth=(26357,47443),rmd=(0,0),income=48000,medicare=0,tax=2323,taxRate=5
Year=2028, age=(62,61),ira=(66986,120576),roth=(40532,72958),rmd=(0,0),income=48000,medicare=0,tax=2323,taxRate=5
Year=2029, age=(63,62),ira=(56612,101902),roth=(55416,99749),rmd=(0,0),income=48000,medicare=0,tax=2323,taxRate=5
Year=2030, age=(64,63),ira=(45719,82295),roth=(71044,127879),rmd=(0,0),income=48000,medicare=0,tax=2323,taxRate=5
Year=2031, age=(65,64),ira=(31582,61707),roth=(87453,157416),rmd=(0,0),income=48000,medicare=2700,tax=2323,taxRate=5
Year=2032, age=(66,65),ira=(17452,36675),roth=(104013,189099),rmd=(0,0),income=48000,medicare=5400,tax=2323,taxRate=5
Year=2033, age=(67,66),ira=(9100,22097),roth=(115018,210750),rmd=(0,0),income=48000,medicare=5400,tax=2322,taxRate=5
Year=2034, age=(68,67),ira=(6855,20502),roth=(120768,221288),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2035, age=(69,68),ira=(4498,18827),roth=(126807,232352),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2036, age=(70,69),ira=(2023,17069),roth=(133147,243970),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2037, age=(71,70),ira=(0,15222),roth=(139228,256168),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2038, age=(72,71),ira=(0,13283),roth=(143490,268977),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2039, age=(73,72),ira=(0,11247),roth=(147964,282426),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2040, age=(74,73),ira=(0,8664),roth=(152662,296547),rmd=(0,445),income=58445,medicare=5400,tax=3668,taxRate=6
Year=2041, age=(75,74),ira=(0,6040),roth=(157596,311374),rmd=(0,356),income=58356,medicare=5400,tax=3655,taxRate=6
Year=2042, age=(76,75),ira=(0,3385),roth=(162775,326943),rmd=(0,257),income=58257,medicare=5400,tax=3641,taxRate=6
Year=2043, age=(77,76),ira=(0,704),roth=(168214,343290),rmd=(0,149),income=58149,medicare=5400,tax=3626,taxRate=6
Year=2044, age=(78,77),ira=(0,0),roth=(173925,358461),rmd=(0,32),income=58032,medicare=5400,tax=3609,taxRate=6
Year=2045, age=(79,78),ira=(0,0),roth=(179921,373685),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2046, age=(80,79),ira=(0,0),roth=(186217,389669),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2047, age=(81,80),ira=(0,0),roth=(192828,406452),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2048, age=(82,81),ira=(0,0),roth=(199769,424075),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2049, age=(83,82),ira=(0,0),roth=(207058,442579),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2050, age=(84,83),ira=(0,0),roth=(214711,462008),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2051, age=(85,84),ira=(0,0),roth=(222746,482408),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2052, age=(86,85),ira=(0,0),roth=(231183,503828),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2053, age=(87,86),ira=(0,0),roth=(240043,526320),rmd=(0,0),income=58000,medicare=5400,tax=3606,taxRate=6
Year=2054, age=(88,87),ira=(0,0),roth=(249345,549936),rmd=(0,0),income=40000,medicare=5400,tax=1363,taxRate=3
Year=2055, age=(89,88),ira=(0,0),roth=(259112,574732),rmd=(0,0),income=40000,medicare=5400,tax=1363,taxRate=3
income=48000,roth=875537,rmd=0,lastTax=0,totalTax=93598

[WangRyan408]

Adding on to this, there is no documentation on what the args are supposed to do.

[liningalex]

Looks good, thank you.