Updated Running Ciphey for Contributors (markdown)

Running-Ciphey-for-Contributors.md

@@ -11,6 +11,8 @@ To run Ciphey with Poetry, in the root directory of Ciphey's repo run:
 poetry run ciphey -t "hello"
 ```
 
+**Note** if you are having dependency issues, run `poetry install`.
+
 We use Poetry because it creates a virtual environment and installs the packages every time you run it. Essentially it's fake-Docker for Python. But it means that if it runs for you via Poetry, it has to run for everyone else too. 
 
 It also fixes dependency issues. Because it installs the required dependencies on run-time it will always have the right ones. No more conflicts!