Fix fundamentals link and remove extraneous header

Author: lcawl

solutions/index.md

@@ -14,7 +14,7 @@ description: Learn about Elastic solutions for search, observability, and securi
 # Solutions and use cases
 
 :::{tip}
-New to Elastic? Refer to [get started](/get-started/the-stack.md) to understand the Elastic Stack and its components, and your deployment options.
+New to Elastic? Refer to [](/get-started/index.md) to understand the Elastic Stack and its components, and your deployment options.
 :::
 
 Users reach for Elastic products, features, and tools for three main use cases: observability, security, and search.
@@ -30,8 +30,6 @@ While these solutions and project types provide pre-built components for common
 2. Getting started with your chosen solution
 3. Implementing specific features and capabilities
 
-## Solution and use case documentation
-
 Learn more in the following sections:
 
 | Solution | Use case |