Replace "zero value" with "not set"

[ivnsch]

https://developer.algorand.org/docs/reference/transactions/#asset-configuration-transaction

ConfigAsset
For re-configure or destroy transactions, this is the unique asset ID. On asset creation, the ID is set to zero.

Although in the required column it says "required, except on create", the mention of "zero" here is confusing and might lead people to setting a literal 0 as id, which makes the transaction fail.

[ivnsch]

Note: at least the Java SDK relies on the encoder to drop keys for "default" values (like 0 for integers), so if someone wants to confirm with the SDKs please inspect the final JSON (corresponding to the message pack encoding).

[barnjamin]

Hi, thanks for the PR! Looks good, but needs to be updated against the new version of the site