Improve issue templates

[mattstein]

Made some pedantic edits to improve brevity and add links to common jumping-off points:

• Curly punctuation (' → ’) because it’s okay to have nice things.
• Link for “search existing issues” to make it more convenient and actionable.
• Reduced verbosity of diagnostic step instruction. (Would be good to link to a “troubleshooting your project” guide here so there isn’t a dead end if the diagnostic is healthy—not sure if such a document exists.)
• Swapped order of bug report’s actual and expected result, assuming that helps better frame problems.
• Made several minor edits for brevity.

[mattstein]

Added a link to the troubleshooting page. :)

[rfay]

Thanks for the great work!

[rfay]

Awesome thanks!