nbody readme update (oneapi-src#581)

Updated Nbody with instructions for how to run on Devcloud.

Author: bdmoore1

DirectProgramming/DPC++/N-BodyMethods/Nbody/README.md

@@ -23,6 +23,9 @@ Third party program Licenses can be found here: [third-party-programs.txt](https
 
 ## Building the Program for CPU and GPU
 
+### Running Samples In DevCloud
+Running samples in the Intel DevCloud requires you to specify a compute node. For specific instructions, jump to [Run the Nbody sample on the DevCloud](#run-nbody-on-devcloud)
+
 ### Include Files  
 The include folder is located at `%ONEAPI_ROOT%\dev-utilities\latest\include` on your development system.
 
@@ -92,3 +95,122 @@ Below are the default parameters:
     # Average Performance : 112.09 +- 0.56002
     ===============================
     Built target run
+
+### Running the Hidden Markov Model sample in the DevCloud<a name="run-nbody-on-devcloud"></a>
+1.  Open a terminal on your Linux system.
+2.	Log in to DevCloud.
+```
+ssh devcloud
+```
+3.	Download the samples.
+```
+git clone https://github.com/oneapi-src/oneAPI-samples.git
+```
+
+4. Change directories to the  Hidden Markov Model sample directory.
+```
+cd ~/oneAPI-samples/DirectProgramming/DPC++/N-bodyMethods/Nbody
+```
+#### Build and run the sample in batch mode
+The following describes the process of submitting build and run jobs to PBS.
+A job is a script that is submitted to PBS through the qsub utility. By default, the qsub utility does not inherit the current environment variables or your current working directory. For this reason, it is necessary to submit jobs as scripts that handle the setup of the environment variables. In order to address the working directory issue, you can either use absolute paths or pass the -d \<dir\> option to qsub to set the working directory.
+
+#### Create the Job Scripts
+1.	Create a build.sh script with your preferred text editor:
+```
+nano build.sh
+```
+2.	 Add this text into the build.sh file:
+```
+source /opt/intel/inteloneapi/setvars.sh > /dev/null 2>&1
+mkdir build
+cd build
+cmake ..
+make
+```
+
+3.	Save and close the build.sh file.
+
+4.	Create a run.sh script with with your preferred text editor:
+```
+nano run.sh
+```
+
+5.	 Add this text into the run.sh file:
+```
+source /opt/intel/inteloneapi/setvars.sh > /dev/null 2>&1
+cd build
+make run
+```
+6.	Save and close the run.sh file.
+
+#### Build and run
+Jobs submitted in batch mode are placed in a queue waiting for the necessary resources (compute nodes) to become available. The jobs will be executed on a first come basis on the first available node(s) having the requested property or label.
+1.	Build the sample on a gpu node.
+
+```
+qsub -l nodes=1:gpu:ppn=2 -d . build.sh
+```
+
+Note: -l nodes=1:gpu:ppn=2 (lower case L) is used to assign one full GPU node to the job.
+Note: The -d . is used to configure the current folder as the working directory for the task.
+
+2.	In order to inspect the job progress, use the qstat utility.
+```
+watch -n 1 qstat -n -1
+```
+Note: The watch -n 1 command is used to run qstat -n -1 and display its results every second. If no results are displayed, the job has completed.
+
+3.	After the build job completes successfully, run the sample on a gpu node:
+```
+qsub -l nodes=1:gpu:ppn=2 -d . run.sh
+```
+4.	When a job terminates, a couple of files are written to the disk:
+
+    <script_name>.sh.eXXXX, which is the job stderr
+
+    <script_name>.sh.oXXXX, which is the job stdout
+
+    Here XXXX is the job ID, which gets printed to the screen after each qsub command.
+
+5.	Inspect the output of the sample.
+```
+cat run.sh.oXXXX
+```
+You should see output similar to this:
+
+```
+Scanning dependencies of target run
+===============================
+ Initialize Gravity Simulation
+ nPart = 16000; nSteps = 10; dt = 0.1
+------------------------------------------------
+ s       dt      kenergy     time (s)    GFLOPS
+------------------------------------------------
+ 1       0.1     26.405      0.43625     17.019
+ 2       0.2     313.77      0.02133     348.07
+ 3       0.3     926.56      0.021546    344.59
+ 4       0.4     1866.4      0.02152     345
+ 5       0.5     3135.6      0.021458    346
+ 6       0.6     4737.6      0.021434    346.38
+ 7       0.7     6676.6      0.02143     346.45
+ 8       0.8     8957.7      0.021482    345.6
+ 9       0.9     11587       0.021293    348.68
+ 10      1       14572       0.021324    348.16
+
+# Total Time (s)     : 0.62911
+# Average Performance : 346.36 +- 1.3384
+===============================
+Built target run
+```
+
+6.	Remove the stdout and stderr files and clean-up the project files.
+```
+rm build.sh.*; rm run.sh.*; make clean
+```
+7.	Disconnect from the Intel DevCloud.
+```
+exit
+```
+### Build and run additional samples
+Several sample programs are available for you to try, many of which can be compiled and run in a similar fashion to this sample. Experiment with running the various samples on different kinds of compute nodes or adjust their source code to experiment with different workloads.