feat: new plot sankey 桑基图

[hustcc]

• layout
• adaptor
• tests
• example
• docs

[github-actions]

😭 Deploy PR Preview 8423f1a failed. Build logs

_{🤖 By surge-preview}

[coveralls]

Pull Request Test Coverage Report for Build 395644599

• 121 of 121 (100.0%) changed or added relevant lines in 9 files are covered.
• 6 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.04%) to 96.677%

---

Files with Coverage Reduction	New Missed Lines	%
src/adaptor/geometries/base.ts	1	98.52%
src/adaptor/conversion-tag.ts	2	92.54%
src/plots/scatter/adaptor.ts	3	91.53%

Totals
Change from base Build 382637271:	-0.04%
Covered Lines:	4125
Relevant Lines:	4162

---

💛 - Coveralls

[lgtm-com]

This pull request introduces 3 alerts when merging fe7aaa1 into cdc99d1 - view on LGTM.com

new alerts:

• 3 for Unused variable, import, function or class

[lgtm-com]

This pull request introduces 3 alerts when merging 25c6e97 into cdc99d1 - view on LGTM.com

new alerts:

• 3 for Unused variable, import, function or class

[lgtm-com]

This pull request introduces 1 alert when merging 51316a8 into cdc99d1 - view on LGTM.com

new alerts:

• 1 for Unused variable, import, function or class

[lgtm-com]

This pull request introduces 1 alert when merging 82e6b22 into 59d636a - view on LGTM.com

new alerts:

• 1 for Unused variable, import, function or class

[lgtm-com]

This pull request introduces 1 alert when merging 68fc461 into 59d636a - view on LGTM.com

new alerts:

• 1 for Unused variable, import, function or class

[lgtm-com]

This pull request introduces 1 alert when merging 9324328 into 59d636a - view on LGTM.com

new alerts:

• 1 for Unused variable, import, function or class

[hustcc]

@me-momo 要来看看 types 定义吗，把把关~