Add full ACS

[MaxGhenis]

For example, here are the files for 2019:

• Person: https://www2.census.gov/programs-surveys/acs/data/pums/2019/1-Year/csv_pus.zip
• Household: https://www2.census.gov/programs-surveys/acs/data/pums/2019/1-Year/csv_hus.zip

Each includes two CSV files which need to be concatenated. I don't think the ACS has a family concept. I'm speaking tomorrow with someone who built tax units from the ACS to use with taxcalc, so I'll report back on how we can do that.

[MaxGhenis]

@baogorek @kklu78