Release of v1.5.5

What's Changed

• CMake: Bump minimum version by @jschueller in #230
• Improved concurrency for multi-threaded indexing by @nigels-com in #236

New Contributors

• @jschueller made their first contribution in #230
• @nigels-com made their first contribution in #236

Full Changelog: v1.5.4...v1.5.5

(See full discussion on the need to benchmark your data in #236 )

For 4 threads vs 1 thread