[EEGUploader] quick visible message at the top of the module screen before 26 release

[christinerogers]

• per EEG Meeting discussion June 5: Out of time to address this issue #9191 before the 26 release so as an emergency documentation patch:

• [ ] Christine will add a sentence to the module readme to say that data won't show in the EEG Browser yet, as of the 26 release - that will be a feature for the 27 release (shorter way to say this: "beta")

• [ ] Laetitia will add suggested wording so that it appears in (a) help text dropdown and (b) so that is is visible at the top of the EEG Uploader modules.

This is at Samir's request (and his actual suggestions). cc @driusan @ridz1208 as a heads-up before 26 is released. (tagging it critical to catch your eye)

[christinerogers]

this was resolved by #9296, marking it as closed and done