docs: architecture documentation updates

[ciaranmcveigh5]

• updates to architecture document to include DutyBuilderRegistration

category: docs
ticket: #849

[codecov]

Codecov Report

Merging #903 (2349165) into main (771d227) will increase coverage by 0.35%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #903      +/-   ##
==========================================
+ Coverage   54.44%   54.79%   +0.35%     
==========================================
  Files         114      114              
  Lines       12342    12342              
==========================================
+ Hits         6719     6763      +44     
+ Misses       4646     4601      -45     
- Partials      977      978       +1     

Impacted Files	Coverage Δ
core/qbft/qbft.go	81.11% <0.00%> (+9.44%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 771d227...2349165. Read the comment docs.