change names of commands and make it positional

mirva/mirva.py

@@ -62,7 +62,7 @@ class Mirva:
                     )
                 )
 
-        if self.run_commands["generator"]:
+        if self.run_commands["build"]:
             self.get_config()
             self.create_posts()
             self.write_index()
@@ -202,11 +202,11 @@ class Mirva:
             help="Force regeneration of middle sized images",
         )
         parser.add_argument(
-            "--command",
-            "-c",
             default="all",
+            dest="command",
             action="store",
-            choices=["all", "config", "generator"],
+            nargs="?",
+            choices=["all", "config", "build"],
             help="Run only part of the process. Defaults to all. Config is run always if it doesn't exist.",
         )
 
@@ -215,8 +215,7 @@ class Mirva:
             "config": self.options.command == "config"
             or self.options.command == "all"
             or not os.path.exists(self.config_file),
-            "generator": self.options.command == "generator"
-            or self.options.command == "all",
+            "build": self.options.command == "build" or self.options.command == "all",
         }
 
     def get_index(self, posts):