Improve documentation, also add organization command

README.md

@@ -3,6 +3,7 @@
 Tools to manage an Ultrastar DX song library. Features include:
 
 1. Deduplication
+2. Organization
 
 ## Setup
 
@@ -14,10 +15,30 @@ pip install -r requirements.txt
 
 ## Run
 
-### Deduplication
-
-If your song library is stored at `/path/to/library`, run:
+We assume that your song library is stored at `$SONG_LIBRARY`. Replace this placeholder when running the command, or just set the variable, e.g., like this:
 
 ```bash
-python3 -m karaokatalog.deduplicate /path/to/library
+export SONG_LIBRARY=/path/to/library
+```
+
+### Deduplication
+
+**Find and delete exactly duplicated songs**, i.e., songs with the same title and artist that also consist of exactly the same files in the directory.
+
+⚠️ This will _irreversibly_ delete all song folders it considers to be exact duplicates.
+
+ℹ️ Deduplication is (mostly) risk-free: As it only deletes exact duplicates, you will not lose any data (given that I've made no programming errors, which is why the operation is only _mostly_ risk-free).
+
+```bash
+python3 -m karaokatalog.deduplicate $SONG_LIBRARY
+```
+
+### Organization
+
+**Rename/move every song folder to `$SONG_LIBRARY/<artist>/<title>`.** If such a folder already exists, a number is appended to distinguish.
+
+ℹ️ Moving will not overwrite already existing files, the operation is therefore risk-free.
+
+```bash
+python3 -m karaokatalog.organize $SONG_LIBRARY
 ```