Update CHANGELOG.md

Author: sahar-azizighannad

CHANGELOG.md

@@ -2,6 +2,25 @@
 
 # v1.91.1
 
+## Enhancements
+
+* Updates endpoint for deleting stack from `POST` to `DELETE` and removing `/delete` from endpoint by
+* Updates endpoint for force deleting stack from `POST` to `DELETE` and removing `/force-delete` from endpoint and adding `?force=true` by
+
+## Deprecations
+
+* The `GET` endpoint to return a `StackPlan` by its ID has been deprecated by 
+* The `GET` endpoint to return a list of stack plans for a given stack configuration has been deprecated by 
+* The `POST` endpoint to approve a stack plan has been deprecated by
+* The `POST` endpoint to cancel a stack plan has been deprecated by
+* The `POST` endpoint to discard a stack plan has been deprecated by
+* The `GET` endpoint to return the plan description for a stack plan has been deprecated by
+* The `AwaitTerminal` method to generate a channel that will receive the status of the stack plan has been deprecated by
+* The `AwaitRunning` method to generate a channel that will receive the status of the stack plan has been deprecated by
+* The `GET` endpoint to return a stack plan operation by its ID has been deprecated by
+* The `GET` endpoint to return a stack source by its ID has been deprecated by
+* The `POST` endpoint to package and upload the specified Terraform Stacks configuration files in association with a Stack has been deprecated by
+
 ## Bug Fixes
 
 * Fixes timestamp attribute mapping for deployment runs to use correct API field names (`created-at`/`updated-at` instead of `started-at`/`completed-at`) by @shwetamurali [#1199](https://github.com/hashicorp/go-tfe/pull/1199)