Move WebExt related stuff into a specific folder

src/Background.purs

@@ -2,7 +2,7 @@ module ExampleWebExt.Background where
 
 import Prelude
 
-import Browser.Runtime (Tab, mkListener, onClickedAddListener, onMessageAddListener, tabsSendMessage)
+import Browser.WebExt.Runtime (Tab, mkListener, onClickedAddListener, onMessageAddListener, tabsSendMessage)
 import Effect (Effect)
 import Effect.Class (class MonadEffect)
 import Effect.Class.Console (log)

src/Browser/Runtime.purs

@@ -1,4 +1,4 @@
-module Browser.Runtime (
+module Browser.WebExt.Runtime (
   Tab,
   TabId,
   Message,

src/Content.purs

@@ -3,7 +3,7 @@ module ExampleWebExt.Content where
 import Prelude
 
 import Browser.DOM (getBrowserDom)
-import Browser.Runtime (mkListener, onMessageAddListener, runtimeSendMessage)
+import Browser.WebExt.Runtime (mkListener, onMessageAddListener, runtimeSendMessage)
 import Effect (Effect)
 import Effect.Class.Console (logShow)
 import Effect.Console (log)