chore: explain in readme that imagemagick and ffmpeg must be installe…

…d for local testing (DEV-2558) #479

README.md

@@ -32,6 +32,7 @@ To get started quickly, without reading the details, just execute these commands
 - `poetry self add poetry-exec-plugin`
 - `poetry install`
 - `pre-commit install`
+- `brew install imagemagick ffmpeg`
 
 
 
@@ -144,6 +145,8 @@ Or even a certain method: `pytest test/unittests/test_excel2xml.py::TestExcel2xm
 This is useful in combination with the debugging mode of your IDE, 
 if you want to examine why a single line of code in a test method fails.
 
+Some e2e tests require ImageMagick and ffmpeg to be installed: `brew install imagemagick ffmpeg`
+
 
 
 ## Code style