docs: update changelog for v0.9.1

Author: aschmahmann

CHANGELOG.md

@@ -1,5 +1,16 @@
 # go-ipfs changelog
 
+## v0.9.1 2021-07-20
+
+This is a small bug fix release resolving the following issues:
+1. A regression where the empty CID bafkqaaa could not resolve on gateways [#8230](https://github.com/ipfs/go-ipfs/issues/8230)
+2. A panic on OpenBSD [#8211](https://github.com/ipfs/go-ipfs/issues/8211)
+3. High CPU usage with QUIC [#8256](https://github.com/ipfs/go-ipfs/issues/8256)
+4. High memory usage with TCP [#8219](https://github.com/ipfs/go-ipfs/issues/8219)
+5. Some pubsub issues ([libp2p/go-libp2p-pubsub#427](https://github.com/libp2p/go-libp2p-pubsub/pull/427), [libp2p/go-libp2p-pubsub#430](https://github.com/libp2p/go-libp2p-pubsub/pull/430))
+6. Updated WebUI to [v2.12.4](https://github.com/ipfs/ipfs-webui/releases/tag/v2.12.4)
+7. Fixed the snap deployment [#8212](https://github.com/ipfs/go-ipfs/pull/8212)
+
 ## v0.9.0 2021-06-22
 
 We're happy to announce go-ipfs 0.9.0. This release makes go-ipfs even more configurable with some fun experiments to boot. We're also deprecating or removing some uncommonly used features to make it easier for users to discover the easy ways to use go-ipfs safely and efficiently.