[Docs] State explicitly that Linux PAL is gramine-direct

Signed-off-by: jkr0103 <jitender.kumar@intel.com>

Documentation/index.rst

@@ -388,13 +388,14 @@ executable arguments may be supplied to the :command:`docker run` command.
    :command:`gsc build`.
 
 
-Execute with Linux PAL instead of Linux-SGX PAL
------------------------------------------------
-
-You may select the Linux PAL at Docker run time instead of the Linux-SGX PAL by
-specifying the environment variable :envvar:`GSC_PAL` as an option to the
-:command:`docker run` command. When using the Linux PAL, it is not necessary to
-sign the image via a :command:`gsc sign-image` command.
+Execute with Linux PAL (:program:`gramine-direct`)
+--------------------------------------------------
+
+You may select the Linux PAL (:program:`gramine-direct`) at Docker run time
+instead of the Linux-SGX PAL (:program:`gramine-sgx`) by specifying the
+environment variable :envvar:`GSC_PAL` as an option to the
+:command:`docker run` command. When using the Linux PAL, it is not necessary
+to sign the image via a :command:`gsc sign-image` command.
 
 .. envvar:: GSC_PAL