Merge pull request #2334 from christinerose/edit_irmin-pack-readme

Revision of `irmin-pack` readme

doc/irmin-pack/design/README.md

@@ -1,5 +1,5 @@
-# Irmin-pack design docs
+# `irmin-pack` Design Docs
 
 - [Layered store](./layered_store.md), the design document for the first version of garbage collection (GC) that shipped with [Irmin 3.4](https://github.com/mirage/irmin/releases/tag/3.4.0).
-- [Chunked suffix](./chunked_suffix.md), the design document for the second version of GC that introduced a chunked suffix for disk space saving during a GC. Introduced in [Irmin 3.5](https://github.com/mirage/irmin/releases/tag/3.5.0).
-- [Lower layer](./lower_layer.md), the design document for the third phase of GC that extended it to work for unlimited history stores by archiving instead of deleting data. Will be introduced in Irmin 3.7.
+- [Chunked suffix](./chunked_suffix.md), the design document for the GC's second version, which introduced a chunked suffix for disk space saving during a GC. Introduced in [Irmin 3.5](https://github.com/mirage/irmin/releases/tag/3.5.0).
+- [Lower layer](./lower_layer.md), the design document for the GC's third phase, extending it to work for unlimited history stores by archiving instead of deleting data. Will be introduced in Irmin 3.7.