Add --help output to README, fix superslicer reference

README.md

@@ -1,6 +1,28 @@
 # Spoolman to slicer filament transfer
 Create [SuperSlicer](https://github.com/supermerill/SuperSlicer) filament configuration from the filaments in [Spoolman](https://github.com/Donkie/Spoolman).
 
+## Usage
+
+```sh
+usage: spoolman2slicer.py [-h] [--version] -d DIR
+                          [-s {orcaslicer,prusaslicer,sl1cer,superslicer}]
+                          [-u URL] [-U] [-D]
+
+Fetches filaments from Spoolman and creates slicer filament config files.
+
+options:
+  -h, --help            show this help message and exit
+  --version             show program's version number and exit
+  -d DIR, --dir DIR     the filament config dir
+  -s {orcaslicer,prusaslicer,sl1cer,superslicer}, --slicer {orcaslicer,prusaslicer,sl1cer,superslicer}
+                        the slicer
+  -u URL, --url URL     URL for the Spoolman installation
+  -U, --updates         keep running and update filament configs if they're
+                        updated in Spoolman
+  -D, --delete-all      delete all filament configs before adding existing
+                        ones
+```
+
 ## Prepare for running
 
 Run:
@@ -19,11 +41,7 @@ it creates. They are stored with the filaments' material's name in
 ## Run
 
 ```sh
-./spoolman2slicer.py -d ~/.config/SuperSlicer/filament/
+./spoolman2slicer.py -U -d ~/.config/SuperSlicer/filament/
 ```
 
-If `-D` is given, all ini files are removed in the directory before
-the new ones are created.
-
-`-U` will cause the program to keep running, adding, updating and
-deleting files when the filaments are changed in Spoolman.
+See the other options above.

spoolman2slicer.py

@@ -24,7 +24,7 @@
 SUPERSLICER = "superslicer"
 
 parser = argparse.ArgumentParser(
-    description="Fetches filaments from Spoolman and creates SuperSlicer filament configs.",
+    description="Fetches filaments from Spoolman and creates slicer filament config files.",
 )
 
 parser.add_argument("--version", action="version", version="%(prog)s 0.0.1")