feat: update to new domain

[RMCampos]

This pull request updates email templates and configuration to standardize the support contact information and sender domain for Tasknote. The main changes are to replace the previous personal email and domain with the official Tasknote support email and domain.

Email template updates:

• Updated all references to the support email address in the following templates to use support@tasknote.cc instead of the previous personal email address: email_changed.html, password_change_confirmation.html, password_reset.html, and sign_up_confirmation.html. [1] [2] [3] [4] [5]

Configuration changes:

• Changed the Mailgun configuration in application.yml to use the tasknote.cc domain and no-reply@tasknote.cc as the sender email.