feat: impl scheme command (partial)

src/caelestia/subcommands/scheme.py

@@ -1,5 +1,7 @@
 from argparse import Namespace
 
+from caelestia.utils.scheme import get_scheme
+
 
 class Command:
     args: Namespace
@@ -8,4 +10,16 @@ class Command:
         self.args = args
 
     def run(self) -> None:
-        pass
+        scheme = get_scheme()
+
+        if self.args.random:
+            scheme.set_random()
+        elif self.args.name or self.args.flavour or self.args.mode:
+            if self.args.name:
+                scheme.name = self.args.name
+            if self.args.flavour:
+                scheme.flavour = self.args.flavour
+            if self.args.mode:
+                scheme.mode = self.args.mode
+        else:
+            print(scheme)