Update contracts release documentation

[maurelian]

Adds a new page to the smart contracts devdocs outlining the contracts release process.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.72%. Comparing base (09d9b1e) to head (a61c444).
⚠️ Report is 22 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #17719      +/-   ##
===========================================
+ Coverage    74.31%   80.72%   +6.41%     
===========================================
  Files          172      117      -55     
  Lines        10955     6170    -4785     
===========================================
- Hits          8141     4981    -3160     
+ Misses        2670     1189    -1481     
+ Partials       144        0     -144     

Flag	Coverage Δ
cannon-go-tests-64	?
contracts-bedrock-tests	80.72% <ø> (ø)

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see 55 files with indirect coverage changes

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