runtime: Only require 'pid' in the state for created/running statuses

Because during creation (before 'created') we may not have a container
process yet (e.g. if we're still reading the configuration or setting
up cgroups), and in the 'stopped' phase the PID is no longer
meaningful.

Also add OPTIONAL/REQUIRED and remove colons for consistency with the
config.md.

Signed-off-by: W. Trevor King <[email protected]>

Author: wking

runtime.md

@@ -7,25 +7,27 @@ Whether other entities using the same, or other, instance of the runtime can see
 
 ## State
 
-The state of a container MUST include, at least, the following properties:
+The state of a container includes the following properties:
 
-* **`ociVersion`**: (string) is the OCI specification version used when creating the container.
-* **`id`**: (string) is the container's ID.
+* **`ociVersion`** (string, REQUIRED) is the OCI specification version used when creating the container.
+* **`id`** (string, REQUIRED) is the container's ID.
 This MUST be unique across all containers on this host.
 There is no requirement that it be unique across hosts.
-* **`status`**: (string) is the runtime state of the container.
+* **`status`** (string, REQUIRED) is the runtime state of the container.
 The value MAY be one of:
     * `created`: the container has been created but the user-specified program has not yet been executed
     * `running`: the container has been created and the user-specified program is running
     * `stopped`: the container has been created and the user-specified program has been executed but is no longer running
 
     Additional values MAY be defined by the runtime, however, they MUST be used to represent new runtime states not defined above.
-* **`pid`**: (int) is the ID of the container process, as seen by the host.
-* **`bundlePath`**: (string) is the absolute path to the container's bundle directory.
+* **`pid`** (int, REQUIRED when `status` is `created` or `running`) is the ID of the container process, as seen by the host.
+* **`bundlePath`** (string, REQUIRED) is the absolute path to the container's bundle directory.
 This is provided so that consumers can find the container's configuration and root filesystem on the host.
-* **`annotations`**: (map) contains the list of annotations associated with the container.
+* **`annotations`** (map, OPTIONAL) contains the list of annotations associated with the container.
 If no annotations were provided then this property MAY either be absent or an empty map.
 
+The state MAY include additional properties.
+
 When serialized in JSON, the format MUST adhere to the following pattern:
 
 ```json