Kotest fixes and assertion library documentation improvements ### Kotest runner - Support Focus and Bang (#62, !88) - Stop crashing on KJS (#59, !89) - Document which Kotest features are configured by Prepared (d87da612, !88) ### Documentation - Remove the warning about Strikt being inactive (#68, f5bf7532, !86) - Mention the Truthish assertion library (#61, 8df3e8f2, !86) - Mention Power Asser (41961dff, !86) - Link the documentation website in the main README (!87) ### Dependency upgrades - Kotest 5.9.1