Add more explicit inkscape dependency to readme and errors

Author: mateosss

README.md

@@ -35,6 +35,18 @@ not get deleted, as the main script `matter.py` is needed for future grub
 updates made by your system. Also if you wan't to uninstall matter you should do
 it from there as well.
 
+## Dependencies
+
+Matter will inform you of any missing dependencies, but here is a list anyways:
+
+- `inkscape` (**Main dependency**): This brings the `convert` command from
+  `imagemagick` with best svg to png conversion.
+- `update-grub`, `grub-mkconfig`, and `grub-mkfont`: General grub utilities
+  needed, if you don't have these, please create an issue with more information
+  about your system as I've only worked on systems that have these commands.
+- `grub2-theme-preview` (Optional): For testing results (`--test/-t` argument)
+  without rebooting.
+
 # Usage
 
 ## Help

matter.py

@@ -219,7 +219,10 @@ def is_icon_downloaded(icon_name):
 
 def convert_icon_svg2png(icon_name):
     if not has_command("convert"):
-        error("Stop. The convert command from imagemagick was not found")
+        error(
+            "Stop. The `convert` command from imagemagick was not found",
+            "Consider installing `inkscape`",
+        )
     if not has_command("inkscape"):
         warning("Resulting icons could look a bit off, consider installing inkscape")
     color = (