Remove doubled sentences in presubmission template

[cmarmo]

This pull request removes doubled paragraphs in the presubmission issue template.
Thanks for considering it.

[dhomeier]

Thanks; agreeing that these were mostly redundant, but see comments on restructuring this further.

[dhomeier]

Thanks, just one tiny change left that could be taken care of here: there's a missing space after the Astropy: entry.

[cmarmo]

there's a missing space after the Astropy: entry.

Indeed! Done. :)

[lwasser]

@cmarmo @cmarmo THANK YOU for this pr! in the future once you have one "approval" from the editorial team, please do feel free to merge. The only exception might be if it is a significant change to our review process - then we'd want a few more team members to review / discuss if needed! 👐🏻

[lwasser]

@all-contributors please add @dhomeier for code, review

[allcontributors]

@lwasser

I've put up a pull request to add @dhomeier! 🎉