Only allow single container operation

As per the discussions in #1156 , we think it's a bad
idea to allow multi container operations in runc. So
revert it.

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>

man/runc-delete.8.md

@@ -1,8 +1,8 @@
 # NAME
-   runc delete - delete any resources held by one or more containers often used with detached containers
+   runc delete - delete any resources held by the container often used with detached container
 
 # SYNOPSIS
-   runc delete [command options] <container-id> [container-id...]
+   runc delete [command options] <container-id>
 
 Where "<container-id>" is the name for the instance of the container.
 

man/runc-pause.8.md

@@ -2,7 +2,7 @@
    runc pause - pause suspends all processes inside the container
 
 # SYNOPSIS
-   runc pause <container-id> [container-id...]
+   runc pause <container-id>
 
 Where "<container-id>" is the name for the instance of the container to be
 paused. 

man/runc-resume.8.md

@@ -2,7 +2,7 @@
    runc resume - resumes all processes that have been previously paused
 
 # SYNOPSIS
-   runc resume <container-id> [container-id...]
+   runc resume <container-id>
 
 Where "<container-id>" is the name for the instance of the container to be
 resumed.

man/runc-start.8.md

@@ -1,12 +1,12 @@
 # NAME
-   runc start - start signals a created container to execute the user defined process
+   runc start - start executes the user defined process in a created container
 
 # SYNOPSIS
-   runc start <container-id> [container-id...]
+   runc start <container-id>
 
 Where "<container-id>" is your name for the instance of the container that you
 are starting. The name you provide for the container instance must be unique on
 your host.
 
 # DESCRIPTION
-   The start command signals the container to start the user's defined process.
+   The start command executes the user defined process in a created container.