Revise README structure and enhance content

profile/README.md

@@ -4,20 +4,29 @@
 
 <!-- Social links -->
 [𝕏]: https://x.com/hashintel
+[linkedin]: https://linkedin.com/company/hashintel
 
 <!-- Site links -->
 [hash.ai]: https://app.hash.ai/?utm_medium=organic&utm_source=github_readme_hashintel-profile_root
 [hash.dev]: https://hash.dev/?utm_medium=organic&utm_source=github_readme_hashintel-profile_root
 
-### Welcome to HASH 👋
+## HASH
 
-We create knowledge management and decision-making tools:
+**[HASH]** is a self-building knowledge graph and platform for high-trust data and AI.
 
-- **# [HASH]**: open-source, self-building database and platform for high-trust AI
-- **Þ [Block Protocol]**: open standard for composable user interfaces and the applications that embed them
+- Try out the hosted version of HASH at [hash.ai]
+- Browse our developer docs and resources at [hash.dev]
+
+### Underlying technology
+
+HASH is made possible by combining a series of technologies:
+
+- The **Semtype** standard for universal types that can be understood, used and composed by both people and machines
+- The **hgres** high-performance knowledge graph engine written in Rust
+- The **Petrinaut** framework for modeling distributed systems (and the world) using Petri nets
+- The **[Block Protocol]** standard for composable user and AI-defined block-based interfaces and the applications that embed them
 
 ### Around the web
 
-- Try out the hosted version of HASH at [hash.ai]
-- Browse our developer docs and resources at [hash.dev]
 - Follow us on [𝕏]
+- Connect with us on [LinkedIn]