Fix small index typo (open-policy-agent#290)

Author: johnkeates

docs/index.md

@@ -1,6 +1,6 @@
 # Conftest
 
-Cconftest is a utility to help you write tests against structured configuration data. For instance you could write tests for your Kubernetes configurations, or Tekton pipeline definitions, Terraform code, Serverless configs or any other structured data.
+Conftest is a utility to help you write tests against structured configuration data. For instance you could write tests for your Kubernetes configurations, or Tekton pipeline definitions, Terraform code, Serverless configs or any other structured data.
 
 Conftest relies on the Rego language from [Open Policy Agent](https://www.openpolicyagent.org/) for writing the assertions. You can read more about Rego in [How do I write policies](https://www.openpolicyagent.org/docs/how-do-i-write-policies.html) in the Open Policy Agent documentation.