Improve the steps to create a private S3 bucket simpler

[krishnakalyan3]

Based on discussion with @panos-is

a. Naviagte to AWS WebUI -> IAM -> [Roles](https://us-east-1.console.aws.amazon.com/iamv2/home?region=us-east-1#/roles)
b. Create Role -> Custom trust policy 
c. Paste the output of the CLI into the `json` editor and click Next
[Image STS]
d. In the `Add permissions` page click Next
e. The role name must begin with `grid-s3-access-` and click on Create role
[Image Role]
f. You will be redirected to IAM -> Roles. Select your role
g. Click on Add Permissions -> Create Inline Policy and paste the permission policy from the CLI output after replacing the bucket name and click on Review Policy
h. Enter an appropriate name, for example, my-permission-policy-for-grid.
[Image Permission Policy]

What does this PR do?

Explain purpose of PR and any useful context.

[krishnakalyan3]

cc: @oojo12 , @robert-s-lee, @essiequoi, @rlizzo and @alexandercort

[rlizzo]

I like this process. It's a lot more linear than the current explanation and does the same job!