Update README and examples to use `defer db.Close()`

README.md

@@ -41,6 +41,10 @@ type User struct {
 func main() {
 	ctx := context.Background()
 	db, err := kpgx.New(ctx, os.Getenv("POSTGRES_URL"), ksql.Config{})
+	if err != nil {
+		log.Fatalf("unable connect to database: %s", err)
+	}
+	defer db.Close()
 
 	// For querying only some attributes you can
 	// create a custom struct like this:
@@ -247,6 +251,7 @@ func main() {
 	if err != nil {
 		panic(err.Error())
 	}
+	defer db.Close()
 
 	// In the definition below, please note that BLOB is
 	// the only type we can use in sqlite for storing JSON.

examples/all_adapters/all_adapters.go

@@ -48,6 +48,8 @@ func main() {
 		if err != nil {
 			log.Fatalf("unable to open database, reason: %s", err)
 		}
+		defer db.Close()
+
 		_, err = db.Exec(ctx, `CREATE TABLE users (
 		  id serial PRIMARY KEY,
 			age INT,
@@ -64,6 +66,8 @@ func main() {
 		if err != nil {
 			log.Fatalf("unable to open database: %s", err)
 		}
+		defer db.Close()
+
 		_, err = db.Exec(ctx, `CREATE TABLE users (
 			id INT AUTO_INCREMENT PRIMARY KEY,
 			age INT,
@@ -80,6 +84,7 @@ func main() {
 		if err != nil {
 			log.Fatalf("unable to open database: %s", err)
 		}
+		defer db.Close()
 
 		// In the example below NVARCHAR is the format
 		// we are using for storing JSON:
@@ -99,6 +104,7 @@ func main() {
 		if err != nil {
 			log.Fatalf("unable to open database: %s", err)
 		}
+		defer db.Close()
 
 		// In the definition below, please note that BLOB is
 		// the only type we can use in sqlite for storing JSON.

examples/crud/crud.go

@@ -56,6 +56,7 @@ func main() {
 	if err != nil {
 		panic(err.Error())
 	}
+	defer db.Close()
 
 	// In the definition below, please note that BLOB is
 	// the only type we can use in sqlite for storing JSON.