fix(docs): broken link for community contribution lifecycle and processes

[trivikr]

Which problem is this PR solving?

• The current link is broken https://github.com/open-telemetry/community/blob/main/CONTRIBUTING.md

Short description of the changes

• Fixes the broken link for contribution processes which were moved in Add skeleton for maintainer and contributor guidebooks community#2051

[pichlermarc]

thanks 🙌

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.75%. Comparing base (d0fb135) to head (889ed96).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2542      +/-   ##
==========================================
- Coverage   90.80%   90.75%   -0.05%     
==========================================
  Files         169      169              
  Lines        8018     8018              
  Branches     1632     1632              
==========================================
- Hits         7281     7277       -4     
- Misses        737      741       +4     

see 1 file with indirect coverage changes

---- 🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests
• JS Bundle Analysis - Avoid shipping oversized bundles

[trivikr]

Thank you @pichlermarc for reviewing and merging this PR.

Can you approve workflows on #2545?
I want to confirm that it fails the CI, and then push formatting fixes.