Issue #3450132: Replace readme.txt with readme.md and update readme.md

README.md

README.txt

bestreply.info.yml

bestreply.install

bestreply.libraries.yml

bestreply.links.menu.yml

bestreply.links.task.yml

bestreply.module

bestreply.permissions.yml

bestreply.routing.yml

config/install/bestreply.settings.yml

config/schema/bestreply.schema.yml

js/bestreply.js

src/Controller/BestReplyController.php

src/Forms/BestReplyConfigurationForm.php