chore: make clear pg >=12 is supported

Author: steve-chavez

README.md

@@ -17,7 +17,7 @@ Postgres has CSV support on the [COPY](https://www.postgresql.org/docs/current/s
 
 ## Installation
 
-Clone this repo and run:
+PostgreSQL >= 12 is supported. Clone this repo and run:
 
 ```bash
 make && make install
@@ -96,7 +96,7 @@ select csv_agg(x, csv_options(delimiter := E'\t')) from projects x;
 
 You can include a byte-order mark (BOM) to make the CSV compatible with Excel.
 
-```sql
+```
 select csv_agg(x, csv_options(bom := true)) from projects x;
 
       csv_agg