As a user, I can share using registered dapps content types

[crtahlin]

It used to work and should work again, that:

• for .md files, user can open them with Dracula
• tor .txt files also
• for .jpg file, user can open with Photoviewer

Rogelio wrote: https://developer.mozilla.org/en-US/docs/Web/API/Navigator/share canShare As a user, I can share using registered dapps content types

[crtahlin]

Until this associations are implemented, please hide the "open" option in menus.