docs: add badges and update issue template

[dongsam]

Description

closes: #136

Tasks

• add codcov badge
• add godoc badge
• update issue/pr template Bullet Points -> Tasks

References

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Appropriate labels applied
• Targeted PR against correct branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[codecov]

Codecov Report

Merging #137 (fe490b6) into master (cc2de5e) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #137   +/-   ##
=======================================
  Coverage   69.71%   69.71%           
=======================================
  Files          25       25           
  Lines        2262     2262           
=======================================
  Hits         1577     1577           
  Misses        533      533           
  Partials      152      152           

---

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 cc2de5e...fe490b6. Read the comment docs.