docs: improving syntax and grammar (#3653)

#### [Enhancement] Refining Syntax and Grammar in README.md for
philips-labs/terraform-aws Repository

*This commit focuses on enhancing the syntax and grammar within the
README.md file of the philips-labs/terraform-aws repository. The goal is
to improve overall clarity and readability by addressing
language-related issues and ensuring a more polished and professional
presentation of the documentation.*

Author: gottfried basinky

README.md

@@ -48,9 +48,9 @@ This [Terraform](https://www.terraform.io/) module creates the required infrastr
 
 GitHub Actions `self-hosted` runners provide a flexible option to run CI workloads on the infrastructure of your choice. However, currently GitHub does not provide tooling to automate the creation and scaling of action runners. This module creates the AWS infrastructure to host action runners on spot instances. It also provides lambda modules to orchestrate the life cycle of the action runners.
 
-Lambda was chosen as the runtime for two major reasons. First, it allows the creation of small components with minimal access to AWS and GitHub. Secondly, it provides a scalable setup with minimal costs that works on repo level and scales to organization level. The lambdas will create Linux based EC2 instances with Docker to serve CI workloads that can run on Linux and/or Docker. The main goal is to support Docker-based workloads.
+Lambda was selected as the preferred runtime for two primary reasons. Firstly, it enables the development of compact components with limited access to AWS and GitHub. Secondly, it offers a scalable configuration with minimal expenses, applicable at both the repository and organizational levels. The Lambda functions will be responsible for provisioning Linux-based EC2 instances equipped with Docker to handle CI workloads compatible with Linux and/or Docker. The primary objective is to facilitate Docker-based workloads.
 
-A logical question would be, why not Kubernetes? In the current approach, we stay close to how GitHub's action runners are implemented today. The approach is to install the runner on a host where the required software is available. With this setup, we stay quite close to the current GitHub approach. Another logical choice would be AWS Auto Scaling groups. However, this choice would typically require much more permissions at the instance level to GitHub. And besides that, scaling up and down is not trivial.
+A pertinent question may arise: why not opt for Kubernetes? The current strategy aligns closely with the implementation of GitHub's action runners. The chosen approach involves installing the runner on a host where the necessary software is readily available, maintaining proximity to GitHub's existing practices. Another viable option could be AWS Auto Scaling groups. However, this alternative usually demands broader permissions at the instance level from GitHub. Additionally, managing the scaling process, both up and down, becomes a non-trivial task in this scenario.
 
 ## Overview
 
@@ -63,15 +63,15 @@ For receiving the `workflow_job` event by the webhook (lambda), a webhook needs
 
 In AWS an [API gateway](https://docs.aws.amazon.com/apigateway/index.html) endpoint is created that is able to receive the GitHub webhook events via HTTP post. The gateway triggers the webhook lambda which will verify the signature of the event. This check guarantees the event is sent by the GitHub App. The lambda only handles `workflow_job` events with status `queued` and matching the runner labels. The accepted events are posted on a SQS queue. Messages on this queue will be delayed for a configurable amount of seconds (default 30 seconds) to give the available runners time to pick up this build.
 
-The "scale up runner" lambda listens to the SQS queue and picks up events. The lambda runs various checks to decide whether a new EC2 spot instance needs to be created. For example, the instance is not created if the build is already started by an existing runner, or the maximum number of runners is reached.
+The "Scale Up Runner" Lambda actively monitors the SQS queue, processing incoming events. The Lambda conducts a series of checks to determine the necessity of creating a new EC2 spot instance. For instance, it refrains from creating an instance if a build is already initiated by an existing runner or if the maximum allowable number of runners has been reached.
 
 The Lambda first requests a JIT configuration or registration token from GitHub, which is needed later by the runner to register itself. This avoids the case that the EC2 instance, which later in the process will install the agent, needs administration permissions to register the runner. Next, the EC2 spot instance is created via the launch template. The launch template defines the specifications of the required instance and contains a [`user_data`](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/user-data.html) script. This script will install the required software and configure it. The registration token for the action runner is stored in the parameter store (SSM), from which the user data script will fetch it and delete it once it has been retrieved. Once the user data script is finished, the action runner should be online, and the workflow will start in seconds.
 
-Scaling down the runners currently uses a brute-force approach: at a configurable interval, lambda will check every runner (instance) to see if it is busy. In case the runner is not busy it will be removed from GitHub and the instance terminated in AWS. At the moment, there seems to be no other option to scale down more smoothly.
+The current method for scaling down runners employs a straightforward approach: at predefined intervals, the Lambda conducts a thorough examination of each runner (instance) to assess its activity. If a runner is found to be idle, it is deregistered from GitHub, and the associated AWS instance is terminated. Presently, no alternative method appears available for achieving a more gradual scaling down process.
 
-Downloading the GitHub Action Runner distribution can occasionally be slow (more than 10 minutes). Therefore a lambda is introduced that synchronizes the action runner binary from GitHub to an S3 bucket. The EC2 instance will fetch the distribution from the S3 bucket instead of the internet.
+To address potential delays in downloading the GitHub Action Runner distribution, a lambda function has been implemented to synchronize the action runner binary from GitHub to an S3 bucket. This ensures that the EC2 instance can retrieve the distribution from the S3 bucket, mitigating the need to rely on internet downloads, which can occasionally take more than 10 minutes.
 
-Secrets and private keys are stored in SSM Parameter Store. These values are encrypted using the default KMS key for SSM or passing in a custom KMS key.
+Sensitive information such as secrets and private keys is stored securely in the SSM Parameter Store. These values undergo encryption using either the default KMS key for SSM or a custom KMS key, depending on the specified configuration.
 
 ![Architecture](docs/component-overview.svg)