Add Geographical Distribution of Star, Pull Request Creator and Issue Creator in README

[linghengqian]

Fixes #26521.

Changes proposed in this pull request:

• Add Geographical Distribution of Star, Pull Request Creator and Issue Creator in README. Image source: PingCAP. The README of apache/superset also uses PingCAP images.
• For more configuration items, refer to,
  • https://next.ossinsight.io/widgets/official/analyze-repo-stars-map?activity=stars&repo_id=49876476
  • https://next.ossinsight.io/widgets/official/analyze-repo-stars-map?activity=pull-request-creators&repo_id=49876476
  • https://next.ossinsight.io/widgets/official/analyze-repo-stars-map?activity=issue-creators&repo_id=49876476
• Markdown doesn’t seem to support CSS3 very well, and the flexible box model doesn’t work in Markdown, so I used HTML tags directly.
• 

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Before committing this PR, I'm sure that I have checked the following options:

• My code follows the code of conduct of this project.
• I have self-reviewed the commit code.
• I have (or in comment I request) added corresponding labels for the pull request.
• I have passed maven check locally : ./mvnw clean install -B -T1C -Dmaven.javadoc.skip -Dmaven.jacoco.skip -e.
• I have made corresponding changes to the documentation.
• I have added corresponding unit tests for my changes.