[Config Linux] Clarify: App --> Container
[Config Linux] Clarify: App --> Container

Replaces #577

Signed-off-by: Rob Dolin (MSFT) <7737aa8e8feac0c2c2954de8a00c3ede85d230e8@microsoft.com>
wking/opencontainer-specs,hqhq/runtime-spec,wking/opencontainer-runtime-spec,opencontainers/runtime-spec,laijs/specs,opencontainers/specs,hqhq/specs