optimize: update online chat information in README.md

[psxjoy]

• I have registered the PR changes.

Ⅰ. Describe what this PR did

When I attempted to join the chat group, I noticed that some of the information was no longer valid. As a result, I updated the latest contact details (sourced from Seata's official website).

通过readme.md 加群的时候，发现：

1. 现在的联系二维码是图片实现的，不方便后续的更新；
2. 部分的二维码已经失效。

此PR修改了最新的联系方式（信息来源于 seata的官方网站）

Ⅱ. Does this pull request fix one issue?

No.

Ⅲ. Why don't you add test cases (unit test/integration test)?

Not applicable.

Ⅳ. Describe how to verify it

Not applicable.

Ⅴ. Special notes for reviews

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 52.53%. Comparing base (fabccea) to head (4e228fb).

Additional details and impacted files

@@            Coverage Diff            @@
##                2.x    #6938   +/-   ##
=========================================
  Coverage     52.53%   52.53%           
- Complexity     6541     6543    +2     
=========================================
  Files          1122     1122           
  Lines         39858    39858           
  Branches       4666     4668    +2     
=========================================
+ Hits          20940    20941    +1     
  Misses        16925    16925           
+ Partials       1993     1992    -1     

see 4 files with indirect coverage changes

[slievrly]

LGTM. Pls add change info.

[psxjoy]

LGTM. Pls add change info.

Thanks. I have already added.

[xingfudeshi]

LGTM