feature request: Tell how many days an issue has since being opened

[sanlf]

Description

It would be nice to see how many days an issue has been open, to more easily check how new the issue is.

Possible implementation

As I see it, it could be implemented by adding this parameter in the transform function inside lib/search.js. Something like this:

function transform (data) {
  const issues = data.items
    .filter(item => item.assignee === null && item.locked !== true)
    .reduce((acc, item) => {
      return acc.concat({
        title: item.title,
        pr: item.number,
        labels: item.labels,
        state: item.state,
        repo: item.repository_url,
        url: item.html_url,
        assignee: item.assignee,
        assignees: item.assignees,
        locked: item.locked,
        daysOpened: diffDate(item.created_at)
      })
    }, [])

  return issues
}

it would then be a question of creating the function diffDate to get the number of days between the time the issue was created and the current time.