chore: tweak useConsistentArrayType rule documentation

[mrazauskas]

Summary

These are few minor changes in useConsistentArrayType rule documentation:

• "Default" was is move into the description of the option
• the heading is now set in lower case (syntax) to match the option name
• and I used bullet points (similar to useNamingConvention documentation)

Test Plan

N/A

[codspeed-hq]

CodSpeed Performance Report

Merging #3891 will not alter performance

_{Comparing mrazauskas:tweak-useConsistentArrayType-documentation (97fd622) with main (713a76e)}

Summary

✅ 107 untouched benchmarks

[dyc3]

Much more clear and concise. Thank you!