Add function to customize report

[boxuancui]

• Pick what to appear in report.
• Able to customize each chart.

[boxuancui]

Might be able to customize report through

rmarkdown::render(
	...,
	params = list(
		data = data,
		report_configuration = list() ## function name should be the key and associated arguments should be the list value
	)
)

[leppott]

I added the following into the YAML header to get date/time and author of the report.

author: "r Sys.getenv('USERNAME')"
date: "r Sys.time()"