Deploy Public S3 Bucket for chain specs

[educlerici-zondax]

Objective

• Create a public S3 bucket to host chain-spec files where only selected contributors can upload, but anyone with the link can download.
• Additionally, establish a GitHub Action to maintain synchronization between the S3 bucket and the files in the chain-spec repository.

Implementation Steps

• Set up the S3 bucket with the specified access permissions.
• Develop and test the GitHub Action in the chainspec repository.
• Document the S3 bucket access policies and GitHub Action details in the repository's README.