updates gitignore

.gitignore

@@ -1,17 +1,52 @@
-.sass-cache
-
+# ------------------------------------------------------------------------
+# This file specifies intentionally untracked files that Git should ignore
+# - https://git-scm.com/docs/gitignore
+# ------------------------------------------------------------------------
+
+# Numerous always-ignore extensions
+*.bak
+*.cvs
+*.db
+*.diff
+*.err
+*.log
+*.orig
+*.rej
+*.zip
+
+# Ignore all files and directories starting with . or ~ or ._ or ending with ~
+.*
+~*
+*~
+._*
+# but track
+!.babelrc.js
+!.browserslist
+!.editorconfig
+!.gitattributes
+!.github
+!.gitignore
+
+# Ignore all files with .lock extentions
+*.lock
+# but track
+!composer.lock
+
+# OS or Editor files and folders
+*.code-workspace
+*.elc
+*.esproj
+*.komodoproject
+*.sublime*
+*.tmproj*
+
+# Dependencies
 bower_components
-
 node_modules
-
-understrap.zip
-
-dist
-
-dist-product
-
-npm-debug.log
-
 /vendor/
 
-.DS_Store
+# Other Understrap specific files and directories
+phpcs.xml
+dist/
+dist-product/
+**/img