Disallow underscores in module names

Using the preferred file naming scheme of {moduleName}_{someInputURLDerivative}_{date}*, this allows mapping files to modules without ambiguity.

codearchiver/core.py

@@ -235,7 +235,7 @@ class ModuleMeta(type):
 	def __new__(cls, *args, **kwargs):
 		class_ = super().__new__(cls, *args, **kwargs)
 		if class_.name is not None:
-			if class_.name.strip('abcdefghijklmnopqrstuvwxyz_-') != '':
+			if class_.name.strip('abcdefghijklmnopqrstuvwxyz-') != '':
 				raise RuntimeError(f'Invalid class name: {class_.name!r}')
 			if class_.name in cls.__modulesByName:
 				raise RuntimeError(f'Class name collision: {class_.name!r} is already known')
@@ -297,7 +297,7 @@ class Module(metaclass = ModuleMeta):
 	'''An abstract base class for a module.'''
 
 	name: typing.Optional[str] = None
-	'''The name of the module. Modules without a name are ignored. Names must be unique and may only contain a-z, underscores, and hyphens.'''
+	'''The name of the module. Modules without a name are ignored. Names must be unique and may only contain a-z and hyphens.'''
 
 	@staticmethod
 	def matches(inputUrl: InputURL) -> bool: