docs(readme): remove dead architecture link - page no longer exists o…

…n docs

Signed-off-by: Alex C-G <alexcg@outlook.com>

README.md

@@ -68,14 +68,12 @@ Find more install options on [Apple Silicon](https://docs.jina.ai/get-started/in
 
 ### Basic Concepts
 
-Document, Executor and Flow are three fundamental concepts in Jina.
+Document, Executor and Flow are the three fundamental concepts in Jina.
 
 - [**Document**](https://docarray.jina.ai/) is the fundamental data structure.
 - [**Executor**](https://docs.jina.ai/concepts/executor/) is a Python class with functions that use Documents as IO.
 - [**Flow**](https://docs.jina.ai/concepts/flow/) ties Executors together into a pipeline and exposes it with an API gateway.
 
-[The full glossary is explained here.](https://docs.jina.ai/concepts/architecture-overview/)
-
 
 ---