fix(reactant-share): remove support for browser extension

Author: unadlib

README.md

@@ -33,7 +33,6 @@ And for the structured design of the application's business logic, separation of
   - Shared tab
   - SharedWorker
   - ServiceWorker
-  - Browser extension
   - Detached window
   - iframe
 - Server-side Rendering

docs/api/reactant-share/README.md

@@ -7,7 +7,6 @@ A framework for building shared web applications that support multiple windows.
 ## Support
 
 - Shared Tab
-- Browser Extension
 - Shared Worker
 - Service Worker
 - Detached window

docs/shared-app.md

@@ -53,7 +53,6 @@ To build such Shared Web Apps, `reactant-share` was created. reactant-share is b
   - Shared tab
   - SharedWorker
   - ServiceWorker
-  - Browser extension
   - Detached window
   - iframe