Update bulletin with highlights for v0.4.0 release (#4576)

BULLETIN.md

@@ -23,12 +23,25 @@ Highlights and notable changes since v0.3.1:
 ## ⚠️ Command `send_tweet` is REMOVED
 Twitter functionality (and more) is now covered by plugins.
 
-## Memory backend deprecation ⚠️
+## ⚠️ Memory backend deprecation 💾
 The Milvus, Pinecone and Weaviate memory backends were rendered incompatible
 by work on the memory system, and have been removed in `master`. The Redis
 memory store was also temporarily removed; we will merge a new implementation ASAP.
 Whether built-in support for the others will be added back in the future is subject to
 discussion, feel free to pitch in: https://github.com/Significant-Gravitas/Auto-GPT/discussions/4280
 
-## Further fixes and changes
-Take a look at the Release Notes on Github! https://github.com/Significant-Gravitas/Auto-GPT/releases/tag/v0.4.0
+## Document support in `read_file` 📄
+Auto-GPT can now read text from document files, with support added for PDF, DOCX, CSV,
+HTML, TeX and more!
+
+## Managing Auto-GPT's access to commands ❌🔧
+You can now disable set of built-in commands through the *DISABLED_COMMAND_CATEGORIES*
+variable in .env. Specific shell commands can also be disabled using *DENY_COMMANDS*,
+or selectively enabled using *ALLOW_COMMANDS*.
+
+## Further fixes and changes 🛠️
+Other highlights include improvements to self-feedback mode and continuous mode,
+documentation, docker and devcontainer setups, and much more. Most of the improvements
+that were made are not yet visible to users, but will pay off in the long term.
+Take a look at the Release Notes on Github for the full changelog!
+https://github.com/Significant-Gravitas/Auto-GPT/releases