Adding more documentation around Splunk logging

Author: derjust

README.md

@@ -72,6 +72,11 @@ You will need to:
 
 (If you use GitHub Enterprise, you need the API & Login URL. This is usually `https://<GitHub Enterprise Host>/api/v3` and `https://<GitHub Enterprise Host>`.)
 
+By default, all logging goes to STDOUT.
+If you use Splunk for logging, you need the Splunk HEC URL & access token. You can also set the source, sourcetype & index for all
+logged events.
+
+
 Next you need to decide if you'd like to deploy with lambda/API Gateway (follow Step 2a), or as a node server (follow Step 2b)
 
 ### 2a: Deployment with lambda and API Gateway
@@ -291,7 +296,7 @@ for more details.
 
 ### Can I use this shim to connect to GitHub directly from another OpenID client?
 
-Yes. This implementation isn't complete, as it focusses exclusively on 
+Yes. This implementation isn't complete, as it focusses exclusively on
 Cognito's requirements. However, it does follow the OpenID spec, and is
 complete enough to be able to use it as an OpenID connect provider. See the
 missing features section above for one or two caveats.

example-config.sh

@@ -9,6 +9,13 @@ export COGNITO_REDIRECT_URI=# https://<Your Cognito Domain>/oauth2/idpresponse
 # GITHUB_API_URL=# https://<GitHub Enterprise Host>/api/v3
 # GITHUB_LOGIN_URL=# https://<GitHub Enterprise Host>
 
+# Variables required if Splunk logger is used
+# SPLUNK_URL=# https://<Splunk HEC>/services/collector/event/1.0
+# SPLUNK_TOKEN=# Splunk HTTP Event Collector token
+# SPLUNK_SOURCE=# Source for all logged events
+# SPLUNK_SOURCETYPE=# Sourcetype for all logged events
+# SPLUNK_INDEX=# Index for all logged events
+
 # Variables required if deploying with API Gateway / Lambda
 export BUCKET_NAME=# An S3 bucket name to use as the deployment pipeline
 export STACK_NAME=# The name of the stack to create