Getting started is missing .md extension (dotnet#61)

Getting started is missing .md extension

docs/benchmarking_docker.md

@@ -4,7 +4,7 @@ This guide shows how to run a Docker job and benchmark it.
 
 ## Prerequisites
 
-1. You should have followed the [Getting Started](getting_started) tutorial, and have `crank` and `crank-agent` tools available.
+1. You should have followed the [Getting Started](getting_started.md) tutorial, and have `crank` and `crank-agent` tools available.
 2. The sample requires an agent running on a **Linux** machine with Docker installed, or at least on Windows with either Docker for Windows or WSL. 
 
 ## Define the scenario
@@ -91,4 +91,4 @@ The `dockerImageName` is used on the agent to name the container. By setting it
 
 The `dockerContextDirectory` is a path representing the working directory inside the Docker file script. Any path using `./` in the Docker file will be this value. It's relative to the root of the source (the clone of the repository).
 
-the property `port` is used to let the Crank agent detect when the application is ready to accept requests. When specified, the agent will try to ping the expected endpoint until it successfully answers. Another option is to define the property `readyStateText` with some valye that is written on the standard output once the application has started. In the case of a Netty application, the service emits `Httpd started. Listening on: 0.0.0.0/0.0.0.0:8080` when the service is ready. Similarly, an ASP.NET application outputs `Application started. Press Ctrl+C to shut down.`
+the property `port` is used to let the Crank agent detect when the application is ready to accept requests. When specified, the agent will try to ping the expected endpoint until it successfully answers. Another option is to define the property `readyStateText` with some valye that is written on the standard output once the application has started. In the case of a Netty application, the service emits `Httpd started. Listening on: 0.0.0.0/0.0.0.0:8080` when the service is ready. Similarly, an ASP.NET application outputs `Application started. Press Ctrl+C to shut down.`