docs(badge): add todo badge

[appleboy]

fix #2236

Signed-off-by: Bo-Yi Wu appleboy.tw@gmail.com

• With pull requests:
  • Open your pull request against master
  • Your pull request should have no more than two commits, if not you should squash them.
  • It should pass all tests in the available continuous integrations systems such as TravisCI.
  • You should add/modify tests to cover your proposed code changes.
  • If your pull request contains a new feature, please document it on the README.

[codecov]

Codecov Report

Merging #2240 into master will not change coverage.
The diff coverage is 96.68%.

@@           Coverage Diff           @@
##           master    #2240   +/-   ##
=======================================
  Coverage   98.38%   98.38%           
=======================================
  Files          41       41           
  Lines        2288     2288           
=======================================
  Hits         2251     2251           
  Misses         21       21           
  Partials       16       16

Impacted Files	Coverage Δ
render/msgpack.go	100% <ø> (ø)	⬆️
binding/msgpack.go	100% <ø> (ø)	⬆️
binding/binding.go	100% <ø> (ø)	⬆️
render/render.go	100% <ø> (ø)	⬆️
path.go	100% <100%> (ø)	⬆️
auth.go	100% <100%> (ø)	⬆️
gin.go	98.29% <100%> (ø)	⬆️
binding/form_mapping.go	100% <100%> (ø)	⬆️
binding/binding_nomsgpack.go	100% <100%> (ø)	⬆️
render/json.go	87.5% <100%> (ø)	⬆️
... and 13 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 41469bf...950435a. Read the comment docs.

[thinkerou]

LGTM