Edit doc

Author: bjsignalfx

docs/getting-started/linux-manual.md

@@ -139,15 +139,18 @@ $ docker run --rm -e SPLUNK_ACCESS_TOKEN=12345 -e SPLUNK_REALM=us0 \
 
 ### Custom Configuration
 
-When changes to the default configuration file is needed, a custom
-configuration file can be specified and used instead. Use the `SPLUNK_CONFIG`
-environment variable or the `--config` command line argument to provide the 
-path to a file containing custom configuration YAML. Also, environment
-variable `SPLUNK_CONFIG_YAML` is available for specifying custom
-configuration YAML directly. This is useful in environments where access
-to the underlying filesystem is not readily available. For example, in 
-AWS Fargate it is more convenient to pull configuration YAML from a 
-parameter in the AWS Systems Manager Parameter Store.
+When changes to the default configuration YAML file are needed, create a
+custom configuration file. Use environment variable `SPLUNK_CONFIG` or
+command line argument `--config` to provide the path to this file.
+
+Also, you can use environment variable `SPLUNK_CONFIG_YAML` to specify 
+your costum configuration YAML at the command line. This is useful in
+environments where access to the underlying file system is not readily
+available. For example, in AWS Fargate, access to the filesystem is 
+not readily available. There, you can store your custom configuration
+YAML in a parameter in AWS Systems Manager Parameter Store, then in
+your container definition specify `SPLUNK_CONFIG_YAML` to get the
+configuration from the parameter.
 
 > Command line arguments take precedence over environment variables. This
 > applies to `--config` and `--mem-ballast-size-mib`. `SPLUNK_CONFIG` 
@@ -167,15 +170,15 @@ $ docker run --rm -e SPLUNK_ACCESS_TOKEN=12345 -e SPLUNK_REALM=us0 \
 > Use of a SemVer tag over `latest` is highly recommended.
 
 In the case of Docker, a volume mount may be required to load the custom
-configuration file as shown above.
+configuration file, as shown above.
 
-If the custom configuration includes a `memory_limiter` processor then the
+If the custom configuration includes a `memory_limiter` processor, then the
 `ballast_size_mib` parameter should be the same as the
 `SPLUNK_BALLAST_SIZE_MIB` environment variable. See
 [gateway_config.yaml](../../cmd/otelcol/config/collector/gateway_config.yaml)
 as an example.
 
-`SPLUNK_CONFIG_YAML` example:
+The following example shows the `SPLUNK_CONFIG_YAML` environment variable:
 ```bash
 $ CONFIG_YAML=$(cat <<-END
 receivers:
@@ -198,3 +201,7 @@ $ docker run --rm \
     -e SPLUNK_CONFIG_YAML=${CONFIG_YAML} \
     --name otelcol quay.io/signalfx/splunk-otel-collector:latest
 ```
+The YAML in the first command configures the Collector to collect and
+log cpu metrics. The YAML is assigned to parameter `CONFIG_YAML` for
+convenience. `CONFIG_YAML` is expanded and assigned to
+`SPLUNK_CONFIG_YAML` in the subsequent `docker run` command.