README.md: Add step to install ffmpeg

README.md

@@ -4,15 +4,16 @@ A scribble of a python script for audio transcription.
 
 ## Setup
 
-1. Install [python](https://www.python.org/downloads/)
-2. Set up a virtual environment (optional)
+1. Install [ffmpeg](https://ffmpeg.org/download.html)
+2. Install [python](https://www.python.org/downloads/)
+3. Set up a virtual environment (optional)
   - `python -m venv .venv`
   - POSIX: `. .venv/bin/activate`
   - Windows (PowerShell): `.venv\Scripts\Activate.ps1`
     - If PowerShell refuses with “running scripts is disabled on this system,” run
       `Set-ExecutionPolicy -Scope CurrentUser RemoteSigned` once, then try activation again.
   - Windows (cmd.exe): `.venv\Scripts\activate.bat`
-3. Build & Install: `pip install -e .`
+4. Build & Install: `pip install -e .`
 
 ## Usage
 `transcribble --help`