add the first plugins

raven/plugins/ravenlogplugin.py

@@ -0,0 +1,21 @@
+from typing import Optional
+
+from raven.mainwindow import MainWindow
+from raven.pluginbase import PluginBase
+
+
+class RavenLogPlugin(PluginBase):
+    def __init__(self):
+        super(RavenLogPlugin, self).__init__()
+        self.main_window = None
+
+    def create_main_window(self):
+        if not self.main_window:
+            self.main_window = MainWindow()
+        return self.main_window
+
+    def current_file(self) -> Optional[str]:
+        return self.main_window.current_file()
+
+    def create_tab(self, file: str):
+        self.main_window.tabs.create_tab(file)