docs: use ots_ prefix

[mattsse]

makes it easier to navigate to the impl

[codspeed-hq]

CodSpeed Performance Report

Merging #13498 will not alter performance

_{Comparing fix/use-ots- (7ea95c3) with main (f791f39)}

Summary

✅ 73 untouched benchmarks
🆕 4 new benchmarks
⁉️ 4 dropped benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	fix/use-ots-	Change
⁉️	range lookup`	613.9 µs	N/A	N/A
⁉️	any lookup`	20 ms	N/A	N/A
⁉️	`prefix set	preload size: 1000	input size: 997	Vec with binary search lookup`
⁉️	`prefix set	preload size: 1000	input size: 997	Vec with custom cursor lookup`
🆕	range lookup`	N/A	608.6 µs	N/A
🆕	any lookup`	N/A	19.8 ms	N/A
🆕	`prefix set	preload size: 1000	input size: 999	Vec with binary search lookup`
🆕	`prefix set	preload size: 1000	input size: 999	Vec with custom cursor lookup`