Update 01_architecture.mdx

apps/hashdotdev/src/_pages/docs/10_contributing/01_architecture.mdx

@@ -18,9 +18,9 @@ Most entities and types you work with in HASH will be user-created, or generated
 - **Web:** a web is a namespace within an instance that contains **entities** and **types**, which belongs to either a user or an organization.
 - **User:** a single account on an instance, corresponding to a real person, which can be logged into via the HASH application interface.
 - **Organization:** a collectively addressable group of users on an instance.
-- **Worker:** @todo
-- **Flow:** @todo
-- **Goal:** @todo
+- **Worker:** an individual AI agent capable of conducting actions or co-ordinating other agents in service of a goal.
+- **Goal:** a user-defined objective provided in natural language. 
+- **Flow:** a pre-defined set of steps that can be executed by workers.
 - **File:** a binary object stored as a single entity. Files MAY have a more specific system-recognized sub-type (e.g. `Image File`), extending the range of ways in which they can be used in HASH.
 
 A number of other system entity types exist,: