Add all of `ts(function)` to docs.

[xiao-e-yun]

It is hard to know what functions i can use. ts(optional) even not show on examples and docs.

[NyxCode]

docs tests, if the example is not enough If you want to extend the example, feel free to open a PR.

[escritorio-gustavo]

Also, if you use an invalid #[ts(non_sense)] attribute, the compiler error will tell you what the valid attributes are in the current context