docs: fix URLs in README post-experimental move

[arbourd]

• Updates main README.md with new URLs of repositories that have been moved
• Updates URLs for plugins (master -> main)

Dup of #2503 with CLA signed and some more fixes.

[codecov]

Codecov Report

Merging #2600 (ee7be34) into main (85d5110) will increase coverage by 0.01%.
The diff coverage is n/a.

❗ Current head ee7be34 differs from pull request most recent head 4559eaa. Consider uploading reports for the commit 4559eaa to get more accurate results

@@            Coverage Diff             @@
##             main    #2600      +/-   ##
==========================================
+ Coverage   93.00%   93.02%   +0.01%     
==========================================
  Files         138      138              
  Lines        5092     5092              
  Branches     1095     1095              
==========================================
+ Hits         4736     4737       +1     
+ Misses        356      355       -1     

Impacted Files	Coverage Δ
...emetry-core/src/platform/node/RandomIdGenerator.ts	93.75% <0.00%> (+6.25%)	⬆️