Update _delphi_utils_python/data_proc/geomap/README.md

Co-authored-by: Katie Mazaitis <[email protected]>

Author: rafaelcatoia

_delphi_utils_python/data_proc/geomap/README.md

@@ -30,7 +30,7 @@ We support the following geocodes.
 
 The source files are requested from a government URL when `geo_data_proc.py` is run (see the top of said script for the URLs). Below we describe the locations to find updated versions of the source files, if they are ever needed.
 
-- ZIP -> FIPS (county) population tables available from [US Census](https://www.census.gov/geographies/reference-files/time-series/geo/relationship-files.html#par_textimage_674173622). This file contains the population of the intersections between ZIP and FIPS regions, allowing the creation of a population-weighted transform between the two. 24 ZIPs did not have population number information associated to them, so we filled those values manually using information available in  [zipdatamaps website](www.zipdatamaps.com).
+- ZIP -> FIPS (county) population tables available from [US Census](https://www.census.gov/geographies/reference-files/time-series/geo/relationship-files.html#par_textimage_674173622). This file contains the population of the intersections between ZIP and FIPS regions, allowing the creation of a population-weighted transform between the two. As of 4 February 2022, this source did not include population information for 24 ZIPs that appear in our indicators. We have added those values manually using information available from the [zipdatamaps website](www.zipdatamaps.com).
 - ZIP -> HRR -> HSA crosswalk file comes from the 2018 version at the [Dartmouth Atlas Project](https://atlasdata.dartmouth.edu/static/supp_research_data).
 - FIPS -> MSA crosswalk file comes from the September 2018 version of the delineation files at the [US Census Bureau](https://www.census.gov/geographies/reference-files/time-series/demo/metro-micro/delineation-files.html).
 - State Code -> State ID -> State Name comes from the ANSI standard at the [US Census](https://www.census.gov/library/reference/code-lists/ansi.html#par_textimage_3). The first two digits of a FIPS codes should match the state code here.