Update bug report issue template.

[kattni]

Includes the following:

• Adds required field for minimum code example, formatted as code, with applicable description.
• Logs input now renders as code input automatically, and the description now reflects that.
• The Environment section updated with clearer description and value.
• Updates the rest of the descriptions to have consistent punctuation.

PR Checklist:

• All new features have been tested
• All new features have been documented
• I have read the CONTRIBUTING.md file
• I will abide by the code of conduct

[mhsmith]

Please let's not add another required field. There are too many already, and in most of the issues I create, I end up having to put placeholders in them all and then edit the issue after creation to delete them.

I would suggest instead merging some of the existing fields, and editing their titles, descriptions or placeholder text to list the kinds of things that should go into them.

The placeholder text is more visible than the desciption, and it can include HTML comments, so that even if the user doesn't delete them, they won't clutter the issue's appearance. For example, see the Chaquopy templates.

[kattni]

@mhsmith I have updated the template to reduce the required fields, and included more descriptive information in the default values. I feel we should not simplify it further than this.