Update .gitignore file to prevent future oopsies (#311)

Author: TheWitness

.gitignore

@@ -1,5 +1,5 @@
 # +-------------------------------------------------------------------------+
-# | Copyright (C) 2004-2025 The Cacti Group                                 |
+# | Copyright (C) 2004-2026 The Cacti Group                                 |
 # |                                                                         |
 # | This program is free software; you can redistribute it and/or           |
 # | modify it under the terms of the GNU General Public License             |
@@ -18,7 +18,35 @@
 # +-------------------------------------------------------------------------+
 # | http://www.cacti.net/                                                   |
 # +-------------------------------------------------------------------------+
+#
+# For any folder that ignores all subcontent (<folder>/**), you
+# must MANUALLY use 'git add' to include a file as source
+# controlled.  This is to prevent addition of local specific
+# content bleeding into cacti's main sources.
+#
 
+# Ignore vim swap files
+*.swp
+*.rnd
 
-locales/po/*.mo
+# Ignore Cacti config
 config.php
+
+# Ignore any mac DS_Store files
+.DS_Store
+
+# Ignore .well-known folders (certbot)
+.well-known
+
+# Ignore .omc directory
+.omc/**
+
+# Nested .omc
+locales/po/.omc/**
+
+# Ignore language files
+locales/po/*.mo
+
+# Ignore visual studio code
+.vscode/**
+