Update prerequisite IAM permissions, clarify instructions

[tylerwellman-tg]

Description of the Change

This pull request:

• Provides a list of required IAM policies for the roles attached to the EKS cluster and EKS node group, respectively
• Clarifies instructions regarding Amazon EBS CSI driver
  • Contrary to the official AWS documentation, the Amazon EBS CSI driver IAM role is not required to install the Amazon EBS CSI driver
  • For example, a prerequisite to installing the Amazon EBS CSI driver is Creating an IAM OIDC provider for your cluster, however, the TigerGraph cluster can be installed and operate properly without configuring OpenID Connect
  • The Amazon EBS CSI driver does need the following required permissions, however, these IAM permissions are already provided by permissions from AWS managed policies that are required for the EKS worker nodes

     "ec2:CreateSnapshot",
     "ec2:AttachVolume",
     "ec2:DetachVolume",
     "ec2:ModifyVolume",
     "ec2:DescribeAvailabilityZones",
     "ec2:DescribeInstances",
     "ec2:DescribeSnapshots",
     "ec2:DescribeTags",
     "ec2:DescribeVolumes",
     "ec2:DescribeVolumesModifications"
    

• Removes a link to an ftp server
• Fixes a typo

Release Notes

• Clarified the process to install a TigerGraph Cluster on EKS