[idea] use Properties Editor as editor

```
ID: org.eclipse.jdt.ui.PropertiesFileEditor
Class: org.eclipse.jdt.internal.ui.propertiesfileeditor.PropertiesFileEditor
Superclass: org.eclipse.ui.editors.text.TextEditor
Plug-in: org.eclipse.jdt.ui
```

This however makes dependency on JDT, so no going with it.

Also it doesn't understand exclusions like  `!*/help/.*.md.html` (it shows it as comment)
