对 #422 提出解决方案 & toggle方法的优化

[yuannancheng]

Summary

What kind of change does this PR introduce? (check at least one)

• Bugfix: 对 #422 提出解决方案
• Feature
• Code style update
• Refactor
• Docs
• Build-related changes
• Other, please describe: 我修改了methods.js中的toggle方法，使得当图片比初始大小更小时，执行toggle方法会恢复为初始大小。

If changing the UI of default theme, please provide the before/after screenshot:

Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)

You have tested in the following browsers: (Providing a detailed version will be better.)

• Chrome: V.90.0.4430.212
• Firefox
• Safari
• Edge
• IE

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature
• Related documents have been updated
• Related tests have been updated

To avoid wasting your time, it's best to open a feature request issue first and wait for approval before working on it.

Other information:

第一次提PR，不太会用。。

[codecov-commenter]

Codecov Report

Merging #477 (6e83108) into master (84f87cc) will decrease coverage by 0.03%.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##           master     #477      +/-   ##
==========================================
- Coverage   75.91%   75.87%   -0.04%     
==========================================
  Files           8        8              
  Lines        1420     1422       +2     
==========================================
+ Hits         1078     1079       +1     
- Misses        342      343       +1     

Impacted Files	Coverage Δ
src/js/handlers.js	46.26% <50.00%> (+0.03%)	⬆️
src/js/methods.js	88.64% <100.00%> (ø)

---

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 84f87cc...6e83108. Read the comment docs.

[fengyuanchen]

不要提交自动生成的文件，比如 dist 目录下的任何文件。

[fengyuanchen]

感谢提交。针对 #422 已经有更好的解决方案。

[yuannancheng]

啊，好的，那真是抱歉。