add back example in README.rst

Author: yucongalicechen

README.rst

@@ -104,6 +104,27 @@ and run the following ::
 
         pip install .
 
+Example
+-------
+
+Navigate to the directory that contains 1D diffraction patterns that you would like to process.
+Activate the conda environment (`conda activate diffpy.labpdfproc_env`) that contains the package and run the following command ::
+
+        labpdfproc <muD> <path/to/inputfile.txt>
+
+Here replace <muD> with the value of muD for your sample
+and <path/to/inputfile.txt> with the path and filename of your input file.
+For example, if the uncorrected data case is called zro2_mo.xy and is in the current directory
+and it has a muD of 2.5 then the command would be ::
+
+        labpdfproc 2.5 zro2_mo.xy
+
+Please type ::
+
+        labpdfproc --help
+
+for more information on the available options.
+
 Getting Started
 ---------------