Clarify wording for terminal setting and /dev/console

Signed-off-by: Mrunal Patel <[email protected]>

Author: mrunalp

config-linux.md

@@ -147,7 +147,7 @@ In addition to any devices configured with this setting, the runtime MUST also s
 * [`/dev/random`][random.4]
 * [`/dev/urandom`][random.4]
 * [`/dev/tty`][tty.4]
-* [`/dev/console`][console.4]
+* [`/dev/console`][console.4] is setup if terminal is enabled in the config
 * [`/dev/ptmx`][pts.4].
   A [bind-mount or symlink of the container's `/dev/pts/ptmx`][devpts].
 

config.md

@@ -90,7 +90,9 @@ See links for details about [mountvol](http://ss64.com/nt/mountvol.html) and [Se
 
 ## Process configuration
 
-* **`terminal`** (bool, optional) specifies whether you want a terminal attached to that process, defaults to false.
+* **`terminal`** (bool, optional) specifies whether a terminal is attached to that process, defaults to false.
+  On Linux, a psuedoterminal pair is allocated for the container process and the psuedoterminal slave is duplicated on the container process's [standard streams][stdin.3].
+  Also, the psuedoterminal slave is bind mounted at /dev/console.
 * **`cwd`** (string, required) is the working directory that will be set for the executable.
   This value MUST be an absolute path.
 * **`env`** (array of strings, optional) contains a list of variables that will be set in the process's environment prior to execution.
@@ -691,3 +693,4 @@ Here is a full example `config.json` for reference.
 [mount.8-filesystem-independent]: http://man7.org/linux/man-pages/man8/mount.8.html#FILESYSTEM-INDEPENDENT_MOUNT OPTIONS
 [mount.8-filesystem-specific]: http://man7.org/linux/man-pages/man8/mount.8.html#FILESYSTEM-SPECIFIC_MOUNT OPTIONS
 [mount.8]: http://man7.org/linux/man-pages/man8/mount.8.html
+[stdin.3]: http://man7.org/linux/man-pages/man3/stdin.3.html