github: add support for github actions

* dependabot
* checks_build workflow

.github/dependabot.yml

@@ -0,0 +1,9 @@
+---
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: "github: [skip ci]"

.github/workflows/build.yml

@@ -0,0 +1,22 @@
+---
+name: checks_build
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+jobs:
+  check-format:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read # to fetch code (actions/checkout)
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build
+        uses: Tiryoh/actions-mkdocs@v0
+        with:
+          configfile: fmt/mkdocs/mkdocs.yml