Update: Add parse_args() for creating and deleting indexes from CLI, removing environment as a parameter, README.md update

[KevKibe]

Description:

• This PR introduces a new function parse_args() to enable creating and deleting Pinecone indexes directly from the command line.
• It removes the previously used environment parameter, suggesting a potential simplification of the code.
• The PR also includes an update to the README.md file, likely to reflect the changes made to the script's usage instructions.