salt is of type bytes32

[seanyoung]

solang mistakenly uses uint256 as the type for the salt argument. Change this to bytes32 to be compatible with solc.

[LucasSte]

When you use either ... or ..., the grammatical forms before and after the or must be the same. a random value is a noun phrase and it can be explicitly set is a verb clause.

I suggest writing The salt can either be a random value or set explicitly using the syntax.

[seanyoung]

I've re-written this paragraph

[LucasSte]

This paragraph as it stands is very messy. I suggest changing the first part to this setting:

When a new contract is created, its address will be a hash of the constructor arguments (the contract's input). As the salt is concatenated to the input, a contract cannot be created twice with the same arguments. The salt can be set using the {salt: hex"439d399ee3b5b0fae6c8d567a8cbfa22d59f8f2c5fe308fd0a92366c116e5f1a"} syntax or assume a random value if none is given.

The end of it can remain with your wording (no changes here):

Specifying a salt will remove the need for generating a random value at runtime, however
care must be taken to avoid using the same salt more than once. Creating a contract twice
with the same salt and arguments will fail. The salt is of type bytes32.

[seanyoung]

The salt isn't concatenated to the input, the input and the salt are hashed. I've re-phrased that to make that clearer.

It's much better now, thanks