Update .gitignore to include backup and Vim files

Added patterns to ignore backup and Vim files.

Author: Junwo-o

.gitignore

@@ -2,4 +2,14 @@
 
 .DS_Store
 
-.idea/
+.idea/
+
+# Backup files (e.g., file.txt~)
+*~
+
+# Vim swap files (e.g., .file.txt.swp)
+.*.swp
+.*.swo
+
+# Vim undo files (e.g., .file.txt.un~)
+.*.un~