CI: add publish and response workflows (dart-lang/markdown#517)

pkgs/markdown/.github/workflows/no-response.yml

diff --git a/pkgs/markdown/.github/workflows/no-response.yml b/pkgs/markdown/.github/workflows/no-response.yml
new file mode 100644
index 0000000..ac3e456
--- /dev/null
+++ b/pkgs/markdown/.github/workflows/no-response.yml
@@ -0,0 +1,34 @@
+# A workflow to close issues where the author hasn't responded to a request for
+# more information; see https://github.com/godofredoc/no-response for docs.
+
+name: No Response
+
+# Both `issue_comment` and `scheduled` event types are required.
+on:
+  issue_comment:
+    types: [created]
+  schedule:
+    # Every day at 8am
+    - cron: '0 8 * * *'
+
+# All permissions not specified are set to 'none'.
+permissions:
+  issues: write
+
+jobs:
+  noResponse:
+    runs-on: ubuntu-latest
+    if: ${{ github.repository_owner == 'dart-lang' }}
+    steps:
+      - uses: godofredoc/no-response@0ce2dc0e63e1c7d2b87752ceed091f6d32c9df09
+        with:
+          responseRequiredLabel: "needs-info"
+          responseRequiredColor: 4774bc
+          daysUntilClose: 14
+          # Comment to post when closing an Issue for lack of response.
+          closeComment: >
+            Without additional information we're not able to resolve this issue,
+            so it will be closed at this time. You're still free to add more
+            info and respond to any questions above, though. We'll reopen the
+            issue if you do. Thanks for your contribution!
+          token: ${{ github.token }}

pkgs/markdown/.github/workflows/publish.yaml

diff --git a/pkgs/markdown/.github/workflows/publish.yaml b/pkgs/markdown/.github/workflows/publish.yaml
new file mode 100644
index 0000000..fcb7ccb
--- /dev/null
+++ b/pkgs/markdown/.github/workflows/publish.yaml
@@ -0,0 +1,14 @@
+# A CI configuration to auto-publish pub packages.
+
+name: Publish
+
+on:
+  pull_request:
+    branches: [ master ]
+  push:
+    tags: [ 'v[0-9]+.[0-9]+.[0-9]+*' ]
+
+jobs:
+  publish:
+    if: ${{ github.repository_owner == 'dart-lang' }}
+    uses: dart-lang/ecosystem/.github/workflows/publish.yaml@main