add timeouts support for sql database instance (hashicorp#1288)

* add timeouts support for sql database instance

* rm a tag

Author: danawillow

docs/r/sql_database_instance.html.markdown

@@ -229,6 +229,15 @@ when the resource is configured with a `count`.
 * `settings.version` - Used to make sure changes to the `settings` block are
     atomic.
 
+## Timeouts
+
+`google_sql_database_instance` provides the following
+[Timeouts](/docs/configuration/resources.html#timeouts) configuration options:
+
+- `create` - Default is 10 minutes.
+- `update` - Default is 10 minutes.
+- `delete` - Default is 10 minutes.
+
 ## Import
 
 Database instances can be imported using the `name`, e.g.