Add provider example to terraform applying (#36965)

Author: rkoron007

website/docs/language/functions/terraform-applying.mdx

@@ -1,7 +1,7 @@
 ---
-page_title: terraform.applying reference - Functions - Configuration Language  
-description: |-  
-  The terraform.applying symbol enables you to determine if Terraform is currently running an apply operation.  
+page_title: terraform.applying reference - Functions - Configuration Language
+description: |-
+  The terraform.applying symbol enables you to determine if Terraform is currently running an apply operation.
 ---
 
 # The `terraform.applying` symbol
@@ -12,23 +12,33 @@ You can use the `terraform.applying` symbol in your configuration to determine i
 
 Terraform automatically sets `terraform.applying` to `true` when you run an [apply](/terraform/cli/commands/apply) operation, and `false` during any other operation. The [planning mode](/terraform/cli/commands/plan#planning-modes) you run `terraform apply` in does not affect `terraform.applying`, meaning that even in destroy mode, `terraform.applying` is still `true`.
 
-A common example of where `terraform.applying` can be helpful is when you want to use different credentials if Terraform is either planning or applying.
+You can use `terraform.applying` to change Terraform behavior during apply operations. In the following example, Terraform uses your read-only credentials when running a plan operation but uses your write credentials when you run an apply operation: 
 
 ```hcl
 locals {
   aws_read_role_arn  = "arn:aws:iam::XXXXX:role/terraform-read"
   aws_write_role_arn = "arn:aws:iam::XXXXX:role/terraform-full"
 
-  # We only need read-only credentials to plan, so if Terraform is applying 
-  # we want to use our AWS role that allows us to write.
   role_arn = terraform.applying ? local.aws_write_role_arn : local.aws_read_role_arn
 }
+
+provider "aws" {
+  region = "us-west-2"
+
+  assume_role {
+    role_arn     = local.role_arn
+  }
+}
+
 ```
 
-The `terraform.applying` symbol is an ephemeral value, meaning it is only available during Terraform operations and Terraform does not write this value to plan or state files. Additionally, you can only reference `terraform.applying` in ephemeral contexts:
 
-* In a [write-only argument](/terraform/language/resources/ephemeral/write-only)
-* In [ephemeral variables](/terraform/language/values/variables#exclude-values-from-state)  
-* In [local values](/terraform/language/values/locals#ephemeral-values)  
-* In [ephemeral resources](/terraform/language/resources/ephemeral)  
-* In [ephemeral outputs](/terraform/language/values/outputs#ephemeral-avoid-storing-values-in-state-or-plan-files)
+The `terraform.applying` symbol is an ephemeral value and is only available during Terraform operations. Terraform does not write ephemeral values to plan or state files. Additionally, you can only reference `terraform.applying` in the following ephemeral contexts:
+
+- In a [write-only argument](/terraform/language/resources/ephemeral/write-only)
+- In [ephemeral variables](/terraform/language/values/variables#exclude-values-from-state)
+- In [local values](/terraform/language/values/locals#ephemeral-values)
+- In [ephemeral resources](/terraform/language/resources/ephemeral)
+- In [ephemeral outputs](/terraform/language/values/outputs#ephemeral-avoid-storing-values-in-state-or-plan-files)
+- Configuring providers in the `provider` block
+- In [provisioner](/terraform/language/resources/provisioners/syntax) and [connection](/terraform/language/resources/provisioners/connection) blocks