docs: add defaultSequenceKind connection property documentation (#1935)

Adds documentation for the defaultSequenceKind connection property.

Author: olavloite

documentation/connection_properties.md

@@ -22,6 +22,7 @@ The 'Context' value indicates whether the property can only be set when a connec
 | databaserole | Sets the database role to use for this connection. The default is privileges assigned to IAM role |  |  | STARTUP |
 | databoostenabled | Enable data boost for all partitioned queries that are executed by this connection. This setting is only used for partitioned queries and is ignored by all other statements. | false | true, false | USER |
 | ddlintransactionmode | Determines how the connection should handle DDL statements in a read/write transaction. | ALLOW_IN_EMPTY_TRANSACTION | FAIL, ALLOW_IN_EMPTY_TRANSACTION, AUTO_COMMIT_TRANSACTION | USER |
+| defaultsequencekind | The default sequence kind that should be used for the database. This property is only used when a DDL statement that requires a default sequence kind is executed on this connection. |  |  | USER |
 | delaytransactionstartuntilfirstwrite | Enabling this option will delay the actual start of a read/write transaction until the first write operation is seen in that transaction. All reads that happen before the first write in a transaction will instead be executed as if the connection was in auto-commit mode. Enabling this option will make read/write transactions lose their SERIALIZABLE isolation level. Read operations that are executed after the first write operation in a read/write transaction will be executed using the read/write transaction. Enabling this mode can reduce locking and improve performance for applications that can handle the lower transaction isolation semantics. | false | true, false | USER |
 | dialect | Sets the dialect to use for new databases that are created by this connection. | GOOGLE_STANDARD_SQL | GOOGLE_STANDARD_SQL, POSTGRESQL | STARTUP |
 | directed_read | The directed read options to apply to read-only transactions. |  |  | USER |