[Fellowship page] Include extra info in the fellowship page

Feature Request

Description

In each individual fellowship-page it would be useful to:

• remove the rectangle that prompt the EdAdmin action to send Fellowship start email if the email has already been sent;
• add a line with the specialties in the "Details" column;
• add the unavailable periods during the fellowship.

Proposals

A possible proposal is to add "Specialty" in the "Details" column, "Unavailability Period" in the right column and remove the rectangle in case the email for starting the fellowship has already been sent.

Page URL(s)

• https://scipost.org/colleges/fellowships/\[Fellowship_number\]/

Related Issues

This issue relates to #224 as it improves the individual fellowship-pages.