docs(postgres): create-db picks closest region by default, us-east-1 is the fallback (#8082)

create-db v1.2.1 geolocates the caller and provisions in the closest
available region when --region is omitted; us-east-1 is only used when
geolocation fails. Update the stale default-region claim on the
npx-create-db page accordingly.

Author: nurul3101

apps/docs/content/docs/postgres/npx-create-db.mdx

@@ -58,7 +58,7 @@ npx create-db@latest
 
 - The `@latest` tag automatically downloads and runs the latest version of the tool, hence, no global installation required.
 - After a few seconds, you'll receive **connection strings** for both Prisma ORM projects and standard PostgreSQL.
-- The default region is `us-east-1`. You can specify the region where you want to provision the database in using the `--region` flag. See [the section below](#available-cli-options) to view all the CLI options.
+- By default, `create-db` detects your approximate location and provisions the database in the closest available region, falling back to `us-east-1` if detection fails. To choose a region yourself, use the `--region` flag. See [the section below](#available-cli-options) to view all the CLI options.
 
 #### Option 2: Choose a region interactively