updated terragrunt.md

Author: HariSekhon

terragrunt.md

@@ -2,16 +2,21 @@
 
 https://terragrunt.gruntwork.io/
 
-Thin wrapper around [Terraform](terraform.md), uses the same arguments as Terraform and passes them to the `terraform` command.
+"Thin wrapper around [Terraform](terraform.md)" but adds lots of sourcing and templating capabilities.
+
+Uses the same arguments as Terraform and passes them to the `terraform` command.
 
 This was designed to reduce duplication when using Terraform code
 and support things like variables, expressions, functions and relative roots in `provider` and `backend` blocks.
 
-This is mainly applicable where people are deploying modules individually instead of from one larger code base run,
-because Terraform is slow
-(usually because it has to make lots of calls to cloud APIs to determine what changes need to be made).
+Especially useful or running Terraform modules individually to save run time.
+
+In CI/CD pipelines you often only want to deploy the modules which have changed individually instead of the entire
+terraform code base, because Terraform is slow (usually because it has to make lots of calls to cloud APIs to determine
+what changes need to be made).
 
-In that case each module then needs its own backend configuration which is almost the same apart from key file path and is otherwise all duplication, which Terragrunt can source to deduplicate.
+In that case each module then needs its own backend configuration which is almost the same apart from key file path and
+is otherwise all duplication, which Terragrunt can source to deduplicate.
 
 Advocates DRY configuration every 10 seconds, which ironically stands for Don't Repeat Yourself.
 
@@ -21,20 +26,22 @@ Someone needs to create a doc tool to DRY out all the Terragrunt documentation r
 
 [Install doc](https://terragrunt.gruntwork.io/docs/getting-started/install/)
 
-Quickly, if you've got [DevOps-Bash-tools](devops-bash-tools.md), find and install the latest version:
+Quicker if you've got [DevOps-Bash-tools](devops-bash-tools.md) - finds and installs the latest version:
 
 ```shell
 install_terragrunt.sh
 ```
 
-Install autocomplete:
+Install shell autocomplete:
 
 ```shell
 terragrunt --install-autocomplete
 ```
 
 ## Terragrunt Template
 
+Heavily commented with advanced knowledge.
+
 Edit to suit your needs:
 
 [HariSekhon/Terraform - terragrunt.hcl](https://github.com/HariSekhon/Terraform/blob/master/terragrunt.hcl)
@@ -43,7 +50,7 @@ Then run...
 
 ## Plan & Apply
 
-Almost the same commands just swap `terraform` for `terragrunt`:
+Almost the same commands, just swap `terraform` for `terragrunt`:
 
 ```shell
 terragrunt plan