Add slash command for invalid issue

Adds a "/invalid" command that when typed in an issue
will let users know the purpose of GitHub issues and
close the issue.

Signed-off-by: Brett Logan <lindluni@github.com>

.github/workflows/slash-commands.yml

@@ -0,0 +1,31 @@
+# Copyright the Hyperledger Fabric contributors. All rights reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+name: Slash Commands
+on:
+  issue_comment:
+    types:
+      - created
+      - edited
+jobs:
+  notify:
+    name: Invalid Issue Usage
+    if: contains(github.event.comment.body, '/invalid') && github.event.issue.state == 'open'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Comment on Issue
+        uses: lindluni/issue-manager@v1.0.0
+        with:
+          action: comment
+          message: |
+            Thank you for opening this issue.
+
+            GitHub Issues is a tool for tracking bugs, feature requests, and work in general that relates directly to the Fabric codebase. It is not for general help requests. Please use one of the following forums to request help for your issue:
+
+            - RocketChat: https://chat.hyperledger.org
+            - Fabric Mailing List: fabric@lists.hyperledger.org
+      - name: Close Issue
+        uses: lindluni/issue-manager@v1.0.0
+        with:
+          action: close