Add `target="_blank"` to link on Home Assistant issue form on GitHub

This feature request is related to the Home Assistant issue report form on GitHub, not Home Assistant itself.

That said… PLEASE add target="_blank" to the link used to find the documentation related to the integration the GitHub issue is regarding!! Two times now I’m finished with writing the issue, and I’m just finding the link to the documentation. I click the link, which then opens in the same tab, and then I have to navigate back a step and the whole form is cleared! Both times it was half an hour or so down the drain.