Add DuckDB Dialect Support

docs/dialect.md

@@ -24,6 +24,7 @@ The following dialects can be imported from `"sql-formatter"` module:
 - `bigquery` - [GCP BigQuery][]
 - `db2` - [IBM DB2][]
 - `db2i` - [IBM DB2i][] (experimental)
+- `"duckdb"` - [duckdb][]
 - `hive` - [Apache Hive][]
 - `mariadb` - [MariaDB][]
 - `mysql` - [MySQL][]
@@ -78,6 +79,7 @@ You likely only want to use this if your other alternative is to fork SQL Format
 [mysql]: https://www.mysql.com/
 [tidb]: https://github.com/pingcap/tidb/
 [couchbase n1ql]: http://www.couchbase.com/n1ql
+[duckdb]: https://duckdb.org/
 [oracle pl/sql]: http://www.oracle.com/technetwork/database/features/plsql/index.html
 [postgresql]: https://www.postgresql.org/
 [presto]: https://prestodb.io/docs/current/

docs/language.md

@@ -16,6 +16,7 @@ const result = format('SELECT * FROM tbl', { dialect: 'sqlite' });
 - `"bigquery"` - [GCP BigQuery][]
 - `"db2"` - [IBM DB2][]
 - `"db2i"` - [IBM DB2i][] (experimental)
+- `"duckdb"` - [duckdb][]
 - `"hive"` - [Apache Hive][]
 - `"mariadb"` - [MariaDB][]
 - `"mysql"` - [MySQL][]
@@ -55,6 +56,7 @@ See docs for [dialect][] option.
 [mysql]: https://www.mysql.com/
 [tidb]: https://github.com/pingcap/tidb/
 [couchbase n1ql]: http://www.couchbase.com/n1ql
+[duckdb]: https://duckdb.org/
 [oracle pl/sql]: http://www.oracle.com/technetwork/database/features/plsql/index.html
 [postgresql]: https://www.postgresql.org/
 [presto]: https://prestodb.io/docs/current/

src/allDialects.ts

@@ -1,6 +1,7 @@
 export { bigquery } from './languages/bigquery/bigquery.formatter.js';
 export { db2 } from './languages/db2/db2.formatter.js';
 export { db2i } from './languages/db2i/db2i.formatter.js';
+export { duckdb } from './languages/duckdb/duckdb.formatter.js';
 export { hive } from './languages/hive/hive.formatter.js';
 export { mariadb } from './languages/mariadb/mariadb.formatter.js';
 export { mysql } from './languages/mysql/mysql.formatter.js';