adds info for polygons and reorganizes document

geocoder/postal-codes/README.md

@@ -3,8 +3,14 @@ Postal code geocoder (polygons)
 
 ### Function
 
+By following the next steps a table is populated with zipcodes from Australia, Canada, USA and France (identified by iso3) related with their spatial location in terms of polygons.
+
 ### Creation steps
 
+1. Import the four files attached in the section "Datasources".
+
+2. Run sql/build_data_table.sql. Notice that table "postal_code_polygons" should exist in advance with columns: _the_geom_, _adm0_a3_ and _postal_code_.
+
 ### Data Sources
 
 Australian polygons - http://www.abs.gov.au/AUSSTATS/abs@.nsf/DetailsPage/2033.0.55.0012011?OpenDocument
@@ -17,14 +23,21 @@ USA polygons - http://www2.census.gov/geo/tiger/TIGER2013/ZCTA5/tl_2013_us_zcta5
 
 French polygons - http://www.data.gouv.fr/dataset/fond-de-carte-des-codes-postaux
 
-All countries points [GeoNames](www.geonames.org) - http://download.geonames.org/export/zip/allCountries.zip
-
 
 ### Preparation details
 
+The names of the imported files are:
+
+- doc for Australia table
+- gfsa000a11a_e for Canada table
+- tl_2013_us_zcta510 for USA table
+- codes_postaux for France table
+
 # Postal code geocoder (points)
 
-1. Download the allCountries.zip file from [GeoNames](www.geonames.org). Import and rename the table as tmp_zipcode_points. You can follow the manual process explained below instead.
+### Function
+
+By following the next steps a table is populated with zipcodes of different countries (identified by iso3) related with their spatial location in terms of points.
 
 This dataset includes data for the following countries:
 
@@ -35,6 +48,11 @@ IT, LU, SK, LI, PR, IM, NO, PT, PL, FI, JP, CA, DE, HU, PH, SE, VA, YT, MK, FR,
 MH, RO, FO, GF, AD, HR, DZ, GT, AU, AS, BE, AT
 ````
 
+### Creation steps
+
+1. Download the allCountries.zip file from [GeoNames](www.geonames.org). Import and rename the table as tmp_zipcode_points. You can follow the manual process explained below instead.
+
+
 The columns that are loaded are the following ones:
 field_1: corresponding to ISO2
 field_10: corresponds to latitude
@@ -54,6 +72,12 @@ In the first row, add the following columns: iso2, zipcode, lat, long.
 
 Import the file ignoring step 2.
 
+### Data Sources
+
+All countries points [GeoNames](www.geonames.org) - http://download.geonames.org/export/zip/allCountries.zip
+
+### Preparation details
+
 _The big size of the dataset may cause interruptions in the processing of the coordinates after uploading the file, manipulating the file before importing is a faster workaround._