Feature: Slack - receive messages, create threads, send replies (#974)

Co-authored-by: Pranav Raj S <pranav@thoughtwoot.com>

config/integration/apps.yml

@@ -1,6 +1,13 @@
 slack:
-  id: cw_slack
+  id: slack
   name: Slack
-  logo: https://a.slack-edge.com/80588/marketing/img/media-kit/img-logos@2x.png
-  description: "'Be less busy' -  Slack is the chat tool that brings all your communication together in one place. By integrating Slack with SupportBee, you can get notified in your Slack channels for important events in your support desk"
-  button: <a href="https://slack.com/oauth/v2/authorize?scope=incoming-webhook,commands,chat:write&client_id=706921004289.1094198503990"><img alt=""Add to Slack"" height="40" width="139" src="https://platform.slack-edge.com/img/add_to_slack.png" srcset="https://platform.slack-edge.com/img/add_to_slack.png 1x, https://platform.slack-edge.com/img/add_to_slack@2x.png 2x" /></a>
+  logo: slack.png
+  description: "Slack is a chat tool that brings all your communication together in one place. By integrating Slack, you can get notified of all the new conversations in your account right inside your Slack."
+  action: https://slack.com/oauth/v2/authorize?scope=commands,chat:write,channels:manage,channels:join,groups:write,im:write,mpim:write,users:read,users:read.email,chat:write.customize 
+webhooks: 
+  id: webhook
+  name: Webhooks
+  logo: cable.svg
+  description: Webhook events provide you the realtime information about what's happening in your account. You can make use of the webhooks to communicate the events to your favourite apps like Slack or Github. Click on Configure to set up your webhooks.
+  action: /webhook
+