Add a snippets editor
Currently Builder does not have UI for editing snippets. We need to add a snippet editor to preferences so that users can view the built in snippets and modify them or add their own. It should be separated by languages. You will probably need to use “subpages” in Builders preferences engine to perform this. You can see an example of how to do that in the “language preferences” in “libide/preferences/ide-preferences-builtin.c”.