Handle config subcommand case where option doesn't exist in config

Signed-off-by: Jacob Stopak <jacob@initialcommit.io>

Author: initialcommit-io

src/git_sim/config.py

@@ -12,7 +12,7 @@
 from typing import List
 from git.repo import Repo
 from argparse import Namespace
-from configparser import NoSectionError
+from configparser import NoSectionError, NoOptionError
 from git.exc import GitCommandError, InvalidGitRepositoryError
 
 from git_sim.settings import settings
@@ -195,6 +195,9 @@ def add_details(self):
                 except NoSectionError:
                     print(f"git-sim error: section '{section}' doesn't exist in config")
                     sys.exit(1)
+                except NoOptionError:
+                    print(f"git-sim error: option '{option}' doesn't exist in config")
+                    sys.exit(1)
             elif len(self.settings) == 2:
                 value = self.settings[1].strip('"').strip("'").strip("\\")
             section_text = (