fix(changelog.py): modify the CHANGELOG.md generated by cz bump --changelog to the right place

Author: Yusin0903

commitizen/commands/changelog.py

@@ -32,21 +32,28 @@ def __init__(self, config: BaseConfig, args):
             raise NotAGitProjectError()
 
         self.config: BaseConfig = config
-        self.encoding = self.config.settings["encoding"]
-        self.cz = factory.commiter_factory(self.config)
-
-        self.start_rev = args.get("start_rev") or self.config.settings.get(
-            "changelog_start_rev"
-        )
-        self.file_name = args.get("file_name") or cast(
+        changelog_file_name = args.get("file_name") or cast(
             str, self.config.settings.get("changelog_file")
         )
-        if not isinstance(self.file_name, str):
+        if not isinstance(changelog_file_name, str):
             raise NotAllowed(
                 "Changelog file name is broken.\n"
                 "Check the flag `--file-name` in the terminal "
                 f"or the setting `changelog_file` in {self.config.path}"
             )
+        self.file_name = (
+            str(Path(self.config.path.parent) / changelog_file_name)
+            if self.config.path is not None
+            else changelog_file_name
+        )
+
+        self.encoding = self.config.settings["encoding"]
+        self.cz = factory.commiter_factory(self.config)
+
+        self.start_rev = args.get("start_rev") or self.config.settings.get(
+            "changelog_start_rev"
+        )
+
         self.changelog_format = get_changelog_format(self.config, self.file_name)
 
         self.incremental = args["incremental"] or self.config.settings.get(