doc: Fix policies README (#240)

policies/README.md

@@ -10,19 +10,23 @@ CloudQuery SQL Policies for Kubernetes
 You can execute policies with `psql`. For example:
 
 ```bash
-# Execute the whole CISA Policy
-psql -U postgres -f  ./nsa_cisa_v1/policy.sql
+# Set DSN to your PostgreSQL populated by CloudQuery
+export DSN=postgres://postgres:pass@localhost:5432/postgres
+# Execute the NSA CISA Policy
+psql ${DSN} -f  ./nsa_cisa_v1/policy.sql
 ```
 
 This will create all the results in `k8s_policy_results` table which you can query directly, connect to any BI system (Grafana, Preset, AWS QuickSight, PowerBI, ...).
 
 You can also output it into CSV or HTML with the following built-in psql commands:
 
 ```
+# Set DSN to your PostgreSQL populated by CloudQuery
+export DSN=postgres://postgres:pass@localhost:5432/postgres
 # default tabular output
-psql -U postgres -c "select * from k8s_policy_results"
+psql ${DSN} -c "select * from k8s_policy_results"
 # CSV output
-psql -U postgres -c "select * from k8s_policy_results" --csv
+psql ${DSN} -c "select * from k8s_policy_results" --csv
 # HTML output
-psql -U postgres -c "select * from k8s_policy_results" --html
+psql ${DSN} -c "select * from k8s_policy_results" --html
 ```