Modify navigation structure

docs/creating-a-benchmark.md

 ---
-title: Creating a Benchmark
+title: Creating Benchmarks
 has_children: false
 nav_order: 5
 ---

docs/creating-an-execution.md

 ---
 title: Creating an Execution
 has_children: false
+parent: Running Benchmarks
 nav_order: 6
 ---
 

docs/index.md

@@ -12,7 +12,7 @@ permalink: /
 Theodolite is a framework for benchmarking the horizontal and vertical scalability of stream processing engines.
 
 [Get started now](quickstart){: .btn .btn-primary .fs-5 .mb-4 .mb-md-0 .mr-4 }
-[Learn more](benchmarks-and-executions){: .btn .fs-5 .mb-4 .mb-md-0 }
+[Learn the underlying concepts](benchmarks-and-executions){: .btn .fs-5 .mb-4 .mb-md-0 }
 
 ---
 

docs/running-benchmarks.md

 ---
 title: Running Benchmarks
-has_children: false
+has_children: true
 nav_order: 4
 ---
 

docs/theodolite-benchmarks/index.md

 ---
-title: Theodolite Benchmarks
+title: Available Benchmarks
 has_children: false
 nav_order: 7
 ---