(fix) remove broken links to old docs and gitter

Signed-off-by: Brent Hoover <[email protected]>

.github/ISSUE_TEMPLATE/bug.md

@@ -5,9 +5,9 @@ labels: 'bug, needs triage'
 ---
 
 <!--
-Issue tracker is **ONLY** used for reporting bugs. NO NEW FEATURE REQUESTS ACCEPTED. For new features, add an issue in our [Request Feature Request](https://github.com/reactioncommerce/reaction-feature-requests) repository.
+Issue tracker is **ONLY** used for reporting bugs. NO NEW FEATURE REQUESTS ACCEPTED.
 
-Are you looking for help with getting started on Reaction? Please visit our [Reaction documentation](https://docs.reactioncommerce.com/reaction-docs/trunk/getting-started-developing-with-reaction).
+Are you looking for help with getting started on Mailchimp Open Commerce? Please visit our [Open Commerce documentation](https://mailchimp.com/developer/open-commerce/).
 
 
 Prerequisites
@@ -38,4 +38,4 @@ Not obligatory, but suggest a fix/reason for the bug
 ### Versions
 <!--
 (run `npm run version --silent` from your reaction directory)
--->
+-->

.github/ISSUE_TEMPLATE/config.yml

@@ -1,5 +1,5 @@
 blank_issues_enabled: false
 contact_links:
-  - name: Gitter chat
-    url: https://gitter.im/reactioncommerce/reaction
-    about: Please ask and answer questions here.
+  - name: Discord
+    url: https://discord.gg/Bwm63tBcQY
+    about: Please ask and answer questions here.

.github/ISSUE_TEMPLATE/corework.md

@@ -1,13 +1,13 @@
 ---
 name: Core Work
-about: Reaction team development work ticket tracker
+about: Mailchimp Open Commerce team development work ticket tracker
 labels: 'core work'
 ---
 
 <!--
 Core work template is only for tracking work for the internal development cycles of the Reaction team. If you want to report a bug please use the bug report template. 
 
-Are you looking for help with getting started on Reaction? Please visit our [Reaction documentation](https://docs.reactioncommerce.com/reaction-docs/trunk/getting-started-developing-with-reaction).
+Are you looking for help with getting started on Mailchimp Open Commerce? Please visit our [Mailchimp Open Commerce documentation](https://mailchimp.com/developer/open-commerce/).
 -->
 
 

.github/ISSUE_TEMPLATE/questions.md

@@ -1,14 +1,13 @@
 ---
 name: ❓ Questions/Help
-about: If you have questions, please check our gitter chat
+about: If you have questions, please check our Discord server
 labels: 'questions'
 ---
 
 ## ❓ Questions and Help
 
 ### Please note that this issue tracker is not a help form and this issue will be closed.
 
-Please contact us instead. We are active in gitter and twitter:
+Please contact us instead. We are active on Discord:
 
-- [Gitter](https://gitter.im/reactioncommerce/reaction)
-- [Twitter](https://twitter.com/getreaction)
+- [Discord](https://discord.gg/Bwm63tBcQY)