Add documentation for Intel RDT support

Signed-off-by: Wolfgang Pross <wolfgang.pross@intel.com>

docs/source/markdown/options/rdt-class.md

@@ -0,0 +1,7 @@
+####> This option file is used in:
+####>   podman create, run
+####> If file is edited, make sure the changes
+####> are applicable to all of those.
+#### **--rdt-class**=*intel-rdt-class-of-service*
+
+Rdt-class sets the class of service (CLOS or COS) for the container to run in. Based on the Cache Allocation Technology (CAT) feature that is part of Intel's Resource Director Technology (RDT) feature set, all processes of the container will run within the pre-configured COS, that represents a part of the cache. The COS has to be created and configured by means of a pseudo file system (usually mounted at `/sys/fs/resctrl`) that the resctrl kernel driver provides. Assigning the container to a COS requires root privileges and thus doesn't work in a rootless environment. Currently the feature is only supported using `runc` as a runtime. See <https://docs.kernel.org/arch/x86/resctrl.html> for more details on how to create a COS before a container can be assigned to it.

docs/source/markdown/podman-create.1.md.in

@@ -304,6 +304,8 @@ by having one container bind to localhost in the pod, and another connect to tha
 
 Suppress output information when pulling images
 
+@@option rdt-class
+
 @@option read-only
 
 @@option read-only-tmpfs

docs/source/markdown/podman-run.1.md.in

@@ -330,6 +330,8 @@ by having one container bind to localhost in the pod, and another connect to tha
 
 Suppress output information when pulling images
 
+@@option rdt-class
+
 @@option read-only
 
 @@option read-only-tmpfs