message: chore(github): update github issue template headers
  current behavor / expected behavior instead of 'behavior'
diff: Thanks for taking the time to file an issue! Please make sure you've read the
  "Opening Issues" section of our Contributing Guide:
  - https://github.com/Opentrons/opentrons/blob/v3a/CONTRIBUTING.md#opening-issues
  + https://github.com/Opentrons/opentrons/blob/edge/CONTRIBUTING.md#opening-issues
  To ensure your issue can be addressed quickly, please fill out the sections
  below to the best of your ability!
  find that may be related.
  -->
  -## behavior
  +## current behavior
  <!--
  Describe how the software currently behaves and how that differs from how you
  - think the software should behave
  + think the software should behave.
  -->
  ## steps to reproduce
  <!--
  If this is a bug report and there are specific steps we can take to reproduce
  the bug, please list them here. This is a good place to put things like
  - software version, hardware version, and operating system
  + software version, hardware version, and operating system.
  +-->
  +
  +## expected behavior
  +
  +<!--
  + Describe how you think the software should behave.
  -->
  