ci: add workflow for file checksum calculation

.github/workflows/checksum.yml

@@ -0,0 +1,38 @@
+---
+name: Checksum
+
+on: 
+  workflow_dispatch:
+    inputs:
+      link1:
+        description: 'Link #1'
+        type: string
+        required: true
+      link2:
+        description: 'Link #2'
+        type: string
+      link3:
+        description: 'Link #3'
+        type: string
+      link4:
+        description: 'Link #4'
+        type: string
+      link5:
+        description: 'Link $5'
+        type: string
+
+jobs:
+  build:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checksum
+        run: |
+          wget -q \
+            ${{ inputs.link1 }} \
+            ${{ inputs.link2 }} \
+            ${{ inputs.link3 }} \
+            ${{ inputs.link4 }} \
+            ${{ inputs.link5 }}
+          ls -l
+          shasum -a 256 *
+...