Adding removed block docs (#1332)

Signed-off-by: Ronny Orot <ronny.orot@gmail.com>
Co-authored-by: Janos <86970079+janosdebugs@users.noreply.github.com>

CHANGELOG.md

@@ -5,6 +5,7 @@ UPGRADE NOTES:
 
 
 NEW FEATURES:
+* Add support for a `removed` block that allows users to remove resources or modules from the state without destroying them. ([#1158](https://github.com/opentofu/opentofu/pull/1158))
 
 ENHANCEMENTS:
 * Added `templatestring` function that takes a string and renders it as a template using a supplied set of template variables. ([#1223](https://github.com/opentofu/opentofu/pull/1223))
@@ -20,7 +21,7 @@ ENHANCEMENTS:
 * Allow test run blocks to reference previous run block's module outputs ([#1129](https://github.com/opentofu/opentofu/pull/1129))
 * Support the XDG Base Directory Specification ([#1200](https://github.com/opentofu/opentofu/pull/1200))
 * Allow referencing the output from a test run in the local variables block of another run (tofu test). ([#1254](https://github.com/opentofu/opentofu/pull/1254))
-* Add support for a `removed` block that allows users to remove resources or modules from the state without destroying them. ([#1158](https://github.com/opentofu/opentofu/pull/1158))
+* Add documentation for the `removed` block. ([#1332](https://github.com/opentofu/opentofu/pull/1332))
 
 BUG FIXES:
 * Fix view hooks unit test flakiness by deterministically waiting for heartbeats to execute ([$1153](https://github.com/opentofu/opentofu/issues/1153))

website/docs/language/resources/behavior.mdx

@@ -29,6 +29,7 @@ In summary, applying an OpenTofu configuration will:
 
 - _Create_ resources that exist in the configuration but are not associated with a real infrastructure object in the state.
 - _Destroy_ resources that exist in the state but no longer exist in the configuration.
+- _Forget_ resources that exist in the state but no longer in the configuration and are referenced in a `removed` block within the configuration.
 - _Update in-place_ resources whose arguments have changed.
 - _Destroy and re-create_ resources whose arguments have changed but which cannot be updated in-place due to remote API limitations.
 

website/docs/language/resources/syntax.mdx

@@ -117,6 +117,41 @@ For more information about how OpenTofu manages resources when applying a
 configuration, see
 [Resource Behavior](/docs/language/resources/behavior).
 
+## Removing Resources
+
+If you remove a resource block from your configuration, OpenTofu will destroy it as a default behavior.
+
+However, there are instances when you want to remove a resource from your configuration without destroying the
+corresponding infrastructure object. In such cases, you can remove it from the [OpenTofu state](/docs/language/state)
+while allowing it to persist in the remote system.
+
+To achieve this, follow these steps:
+1. Delete the resource from your configuration.
+2. Add a removed block instead, specifying the resource address you want to "forget" in the `from` attribute.
+
+For example:
+```hcl
+removed {
+  from = aws_instance.web
+}
+```
+
+:::note
+
+The address in the `from` attribute cannot include instance keys (for example, "aws_instance.web[0]").
+
+:::
+
+Upon executing `tofu plan`, OpenTofu will indicate that the resource is slated for removal from the state but will not
+be destroyed.
+
+The `removed` block can be used to remove specific resources or modules containing multiple resources. For example:
+```hcl
+removed {
+  from = module.some_module
+}
+```
+
 ## Meta-Arguments
 
 The OpenTofu language defines several meta-arguments, which can be used with