Updated .gitignore file for firebase

.gitignore

-# ignore all files starting with . or ~
-.*
+# ignore all temp files starting with ~
 ~*
 
 # ignore node/grunt dependency directories
@@ -25,4 +24,8 @@ node_modules/
 !.gitlab-ci.yml
 !.eslintrc.*
 
+# ignore building files
 dist/
+
+# ignore firbase temp files
+.firebase/