Update this issue template so that a short description is at the top.

[johnnymatthews]

When you tag an issue, such as #111, GitHub adds a hyperlink and a hover-tooltip. It looks like this:

With the current issue template, the only information that one can read within this tooltip are the checkboxes. This isn't ideal.

Tasks

• Update the issue template so that:
  • The checkboxes are moved further down the template.
  • A one-sentence issue description is added to the top of the template.