chore: add dependabot, remove html comments from post excerpts

.github/dependabot.yml

@@ -0,0 +1,23 @@
+version: 2
+updates:
+  - package-ecosystem: npm
+    directory: /
+    schedule:
+      interval: daily
+    open-pull-requests-limit: 3
+    pull-request-branch-name:
+      separator: '-'
+    groups:
+      patch-updates:
+        patterns:
+          - '*'
+        update-types:
+          - patch
+      minor-updates:
+        patterns:
+          - '*'
+        update-types:
+          - minor
+    ignore:
+      - dependency-name: '*'
+        update-types: ['version-update:semver-major']