feat: Add the ability to set URL on NewButtonBlockElement via .WithURL()

[joshbranham]

This introduces the ability to set the URL for a ButtonBlockElement on an existing instance by calling .WithURL("https://myurl").

Fixes #1085

[crystaljoel]

I just ran into this in a project I was working on, instead of adding the URL as an argument in my fork I added a WithURL method similar to what had been done for adding a style or confirm.

Example

slack.NewButtonBlockElement(...).WithURL(url)

[joshbranham]

I just ran into this in a project I was working on, instead of adding the URL as an argument in my fork I added a WithURL method similar to what had been done for adding a style or confirm.

Example

slack.NewButtonBlockElement(...).WithURL(url)

Good point, I like that better. Happy to rework this to go that route if maintainers would prefer

[parsley42]

Yeah, I'm really loathe to change a function signature. If this needs to be merged, please use e.g. withURL(...), and look for a way to update the documentation so maintainers will find/see it.

[joshbranham]

small typo fix

[joshbranham]

Implemented as suggested, good call!

[parsley42]

LGTM