chore: Add internal list of built-in contexts

[scouten]

No description provided.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 9.80%. Comparing base (9533264) to head (2e1be31).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff            @@
##            main    #180      +/-   ##
========================================
+ Coverage   9.41%   9.80%   +0.39%     
========================================
  Files        324     325       +1     
  Lines      19835   19922      +87     
========================================
+ Hits        1867    1954      +87     
  Misses     17968   17968              

Components	Coverage Δ
Parser test coverage	100.00% <100.00%> (ø)
AsciiDoc spec coverage	1.78% <ø> (+0.30%)	⬆️

[codspeed-hq]

CodSpeed Performance Report

Merging #180 will not alter performance

_{Comparing blocks+is-built-in-context (2e1be31) with main (9533264)}

Summary

✅ 4 untouched benchmarks