feat: add readme

README.md

+# Audio-Renamer
+
+## Usage 
+
+```
+usage: audio-renamer.py [-h] [--dry-run] folders [folders ...]
+
+positional arguments:
+  folders     Folders to run the task on
+
+optional arguments:
+  -h, --help  show this help message and exit
+  --dry-run   Simulate renames
+```
+
+## Format
+
+The hardcoded default format in Amarok syntax is
+
+```
+%albumartist%/%album%{ (%originalyear%)}/{{%disc%-}%track%. }%title%.%extension%
+```