Update README.md

Author: haleemyousef

README.md

@@ -1,2 +1,9 @@
 # Change_Hashcode_for_image
-Are you tired of taking new photos everytime your Facebook Marketplace ad expires? This script solves the problem.
+Are you tired of taking new pictures everytime your Facebook Marketplace ad expires? This python script solves the problem.
+
+How to use:
+copy the Change_Hashcode_for_image.py to the folder where the image/s exist.
+inside Change_Hashcode_for_image.py: change the variable input_file_path to the image name.
+run the script using python3.
+
+This can be used for other purposes. It essentially changes 1 random byte in the input file, which changes the hash of the output file. The hash is used to ban duplicate ads in websites like Facebook Marketplace.