Update ISSUE_TEMPLATE to help define work to be done

[danielduan]

Issue: We create work issues that are not clearly defined. It makes it hard to contribute and work on the ticket and these tickets tend to stay open forever.

What I did

Added a section template to describe the work to be done and help guide what a good work ticket looks like.

[codecov]

Codecov Report

Merging #3257 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3257   +/-   ##
=======================================
  Coverage   35.61%   35.61%           
=======================================
  Files         442      442           
  Lines        9777     9777           
  Branches      897      919   +22     
=======================================
  Hits         3482     3482           
- Misses       5704     5733   +29     
+ Partials      591      562   -29

Impacted Files	Coverage Δ
addons/storysource/src/loader/generate-helpers.js	44.44% <0%> (ø)	⬆️
addons/info/src/components/markdown/code.js	76.92% <0%> (ø)	⬆️
addons/viewport/src/manager/components/Panel.js	36.02% <0%> (ø)	⬆️
addons/knobs/src/components/types/Select.js	24.63% <0%> (ø)	⬆️
lib/ui/src/modules/ui/components/menu_item.js	19.14% <0%> (ø)	⬆️
lib/ui/src/modules/ui/configs/init_panels.js	25% <0%> (ø)	⬆️
addons/knobs/src/react/WrapStory.js	49.42% <0%> (ø)	⬆️
addons/a11y/src/components/WrapStory.js	61.11% <0%> (ø)	⬆️
addons/a11y/src/components/Report/Tags.js	0% <0%> (ø)	⬆️
addons/actions/src/lib/decycle.js	53.52% <0%> (ø)	⬆️
... and 65 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 4cfe34a...ad8a37c. Read the comment docs.