update readme for populating the dummy data

Author: danielstaleiny

db/src/sample_data/README.md

@@ -1,16 +1 @@
-Sample data in this directory was generated using `datafiller` utility
-you can install it like so
-
-```shell
-wget -q https://raw.githubusercontent.com/memsql/datafiller/master/datafiller -O /usr/local/bin/datafiller \
-	&& chmod +x /usr/local/bin/datafiller
-```
-
-after it's installed, you can generate sample data using a comand like the one below
-
-```shell
-( \
-  cd db/src/data && \
-  cat users.sql items.sql subitems.sql | datafiller --size=2 > ../sample_data/data.sql \
-)
-```
+In file `data.sql` we populate with random data our tables with help of csv.