remove utils.py file; use a setting file for delay between updates

utils.py contained two functions. One which wasn't used, and another,
get_settings() which I moved to MarkdownLivePreview.py

Add an entry to the command palette to edit the settings

live-testing/test.md

@@ -1,9 +1 @@
-```
-hello world
-```
-
-```
-second part
-```
-
-hello world
+# hello world