chore(ci): Add a message to the automatic lock. (#71)

Author: calavera

.github/workflows/lock.yml

@@ -19,4 +19,13 @@ jobs:
       - uses: dessant/lock-threads@v4
         with:
           issue-inactive-days: '0'
-          pr-inactive-days: '0'
+          pr-inactive-days: '0'
+          issue-comment: >
+            This issue has been automatically locked.
+            Create a new discussion if you'd like to continue the conversation.
+            https://github.com/cargo-lambda/cargo-lambda/discussions/new?category=general
+          pr-comment: >
+            This pull request has been automatically locked.
+            Create a new discussion if you'd like to continue the conversation.
+            https://github.com/cargo-lambda/cargo-lambda/discussions/new?category=general
+          process-only: 'issues, prs'