Added semantic conventions for the "process" resource

specification/resource/semantic_conventions/README.md

@@ -19,7 +19,7 @@ This document defines standard attributes for resources. These attributes are ty
 
 ## TODOs
 
-* Add more compute units: Process, AppEngine unit, etc.
+* Add more compute units: AppEngine unit, etc.
 * Add Device (mobile) and Web Browser.
 * Decide if lower case strings only.
 * Consider to add optional/required for each attribute and combination of attributes
@@ -113,6 +113,20 @@ Note: The resource attribute `faas.instance` differs from the span attribute `fa
 [ARN]:https://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html
 [FunctionDirectory]: https://github.com/Azure/azure-functions-host/wiki/Retrieving-information-about-the-currently-running-function
 
+### Process
+
+**type:** `process`
+
+**Description:** An operating system process.
+
+| Attribute | Description | Example |
+|---|---|---|
+| process.pid | Process identifier (PID). | `1234` |
+| process.name | Process name. | `OpenTelemetry Collector` |
+| process.command | The process executable. | `cmd/otelcol` |
+| process.commandline | The full command used to launch the process. | `cmd/otecol --config=config.yaml` |
+| process.owner | The username of the user that owns the process. | `root` |
+
 ## Deployment Service
 
 Attributes defining a deployment service (e.g. Kubernetes).