doc: Upgrade guide for v1.35.0 (#3360)

* upgrade guide

* Update docs/guides/1.35.0-upgrade-guide.md

Co-authored-by: John Williams <[email protected]>

---------

Co-authored-by: John Williams <[email protected]>

Author: oarbusi

docs/guides/1.35.0-upgrade-guide.md

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+---
+page_title: "Upgrade Guide 1.35.0"
+---
+
+# MongoDB Atlas Provider 1.35.0: Upgrade and Information Guide
+
+The Terraform MongoDB Atlas Provider version 1.35.0 introduces the following new features and fixes:
+
+## New Resources, Data Sources, and Features
+
+- `mongodbatlas_advanced_cluster` (preview provider 2.0.0) and `mongodbatlas_advanced_cluster` resources now support the new `delete_on_create_timeout` attribute. This flag indicates whether to delete the cluster if the cluster creation times out. The default is `false`. To learn more, see the [mongodbatlas_advanced_cluster](https://registry.terraform.io/providers/mongodb/mongodbatlas/latest/docs/resources/advanced_cluster) resource documentation.
+
+- `mongodbatlas_search_deployment` resource now supports the new `delete_on_create_timeout` attribute. This flag indicates whether to delete the search deployment if the search deployment creation times out. The default is `false`. To learn more, see the [mongodbatlas_search_deployment](https://registry.terraform.io/providers/mongodb/mongodbatlas/latest/docs/resources/search_deployment) resource documentation.
+
+## Bug Fixes
+
+- `mongodbatlas_private_endpoint_regional_mode` resource update wait time has been increased so cluster connection strings are updated. This improves reliability when updating regional mode private endpoints.
+
+## Helpful Links
+
+* [Report bugs](https://github.com/mongodb/terraform-provider-mongodbatlas/issues)
+* [Request Features](https://feedback.mongodb.com/forums/924145-atlas?category_id=370723)
+* [Contact Support](https://docs.atlas.mongodb.com/support/) covered by MongoDB Atlas support plans, Developer and above.