Language guide page on modifiers (control, power, dagger)

[CalMacCQ]

This will soon be a feature of Guppy and ought to be documented. In fact writing a draft of the docs page may be a good way to determine whether this feature is ready for external use.

[CalMacCQ]

@nicolaassolini-qntm I'd quite like to write this but would be great to have input from you.

[nicolaassolini-qntm]

@nicolaassolini-qntm I'd quite like to write this but would be great to have input from you.

@CalMacCQ sure! I'm preparing a test notebook which will be a good start on what can be done!