Fix wording in attribute reference

[alcaeus]

The attribute reference refers to parameters of attributes as "attributes", most likely as a leftover from when it was the annotation reference and wasn't as confusing. The following alternatives come to mind:

• options: this can be confusing and makes for awkward wording, as in "the xyz option is optional" and implies that everything is optional
• arguments: this is most likely the better choice, using the same wording used in general for parameter values in method calls
• parameters: used interchangeably with arguments, but technically incorrect as it refers to the variables listed in a declaration

I would suggest replacing all mentions of option, attribute, etc. when talking about arguments with argument.

[malarzm]

+1 for arguments, PHP docs are also using them https://www.php.net/manual/en/language.attributes.syntax.php

Arguments to the attribute are optional, but are enclosed in the usual parenthesis (). Arguments to attributes can only be literal values or constant expressions. Both positional and named arguments syntax can be used.

[jmikola]