add some instructions to readme

README.md

@@ -14,6 +14,21 @@ The passwords are stored encrypted in sqlite3 database and are decrypted only wh
 - change the master password, which will re-encrypt all passwords in the database so I can access them with the new master password
 - exit the program
 
+## To build the project run:
+```bash
+stack build
+```
+
+## To run the project run:
+```bash
+stack exec HasswordManager-exe
+```
+
+## To run the tests run:
+```bash
+stack test
+```
+
 ## Authors:
 - Jan Wojciechowski
 - Sebastian Jerzykiewicz