Env file

[Reccetech]

Problem

Throughout the docs sometimes we seem to use different conventions in the code samples referring to the account and private key.

In the Environment setup its: MY_ACCOUNT_ID MY_PRIVATE_KEY

In the JS code under "Submit your first Message" its: operatorId operatorKey

In the Java code under create an NFT its: ACCOUNT_ID PRIVATE_KEY

I think we need to standardize on our terms for these two items.

Solution

Align terminology

Alternatives

No response

### Tasks
- [ ] Alignment needs to be made across products (portal/SDKs/tutorials/blogs) on what the standard naming converntion should be