fix: update .gitignore and remove sensitive config.toml, add config.example.toml

.gitignore

@@ -1,3 +1,3 @@
 /target
 .env
-
+config.toml

config.example.toml

@@ -0,0 +1,16 @@
+imap_server = "imap.gmail.com"
+imap_port = 993
+imap_username = "@gmail.com"
+imap_password = ""
+discord_webhook_url = ""
+
+# Ignore emails from these senders (exact match or partial match)
+ignored_senders = [
+    "no-reply@accounts.google.com"
+]
+
+# Ignore emails with these subjects (partial match)
+ignored_subjects = [
+    "Security Alert",
+    "보안"
+]