Add anchor_label method

[shubham0x13]

Added anchor_label method which allows easy anchoring/positioning of label based on predefined anchor points and screen size.

[FoamyGuy]

@shubham0x13 Thanks for working on this. It does seem like a convenient way to anchor to some of the most likely to be used places. But I think I'd like to consider some other options to incorporate the functionality.

If we do include it in this library I think maybe a different name could be better anchor_label feels a little ambiguous between a noun and a verb, taken as a verb the "label" feels redundant since it's on the Label class so can be assumed to deal with the label without needing it called out in the name.

I am kind of leaning towards thinking this functionality should live somewhere else other than the display text library though. There are a handful of other classes that have anchor_point and anchored_position APIs that match the functionality of Label: Any sub-classes of Widget, also AnchoredTileGrid, and AnchoredGroup. I think it would be nice to centralize this functionality somewhere and have the first argument to the function be any object with this API rather than a self instance. That way the function can live in one spot and be used with all of the various types of objects that support it.

I am not 100% decided on where seems like the right place for it to actually live but I am thinking inside of Adafruit_Displayio_Layout makes sense because at it's core the functionality is to help you lay things out on your screen. Perhaps just as a helper function inside of https://github.com/adafruit/Adafruit_CircuitPython_DisplayIO_Layout/blob/main/adafruit_displayio_layout/layouts/__init__.py

Would you be willing to refactor this and move it to a function over there?

[shubham0x13]

@FoamyGuy Thanks! Moved it as suggested and opened a PR there.