add .github folder

includes
- CI workflow
- funding info
- dependabot config

.github/FUNDING.yml

@@ -0,0 +1,3 @@
+# These are supported funding model platforms
+
+github: 2bndy5

.github/dependabot.yml

@@ -0,0 +1,23 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: "weekly"
+    groups:
+      actions:
+        patterns:
+          - "*"
+  - package-ecosystem: cargo
+    directory: /
+    schedule:
+      interval: "daily"
+    groups:
+      cargo:
+        patterns:
+          - "*"

.github/workflows/build.yml

@@ -0,0 +1,24 @@
+name: build and test CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup Rust
+        uses: dtolnay/rust-toolchain@stable
+      - run: cargo build
+      - run: cargo check
+      - run: cargo fmt
+      - run: cargo doc --no-deps
+      - name: save docs as artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: rf24-rs docs
+          path: target/doc