Add CI workflow to do Arduino project-specific linting

On every push or pull request, run Arduino Lint to check for common problems not related to the project code.

Author: per1234

.github/workflows/arduino-lint.yml

@@ -0,0 +1,26 @@
+name: Arduino Lint
+on:
+  push:
+  pull_request:
+  # Scheduled trigger checks for breakage caused by new rules added to Arduino Lint
+  schedule:
+    # run every Saturday at 3 AM UTC
+    - cron: "0 3 * * 6"
+  # See: https://docs.github.com/en/free-pro-team@latest/actions/reference/events-that-trigger-workflows#workflow_dispatch
+  workflow_dispatch:
+  # See: https://docs.github.com/en/free-pro-team@latest/actions/reference/events-that-trigger-workflows#repository_dispatch
+  repository_dispatch:
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Arduino Lint
+        uses: arduino/arduino-lint-action@v1
+        with:
+          official: true
+          library-manager: submit # Change this to "update" once the library has been added to the Library Manager index.

README.md

@@ -1,6 +1,7 @@
 # Arduino_Portenta_OTA
 
 [![Compile Examples](https://github.com/arduino-libraries/Arduino_Portenta_OTA/workflows/Compile%20Examples/badge.svg)](https://github.com/arduino-libraries/Arduino_Portenta_OTA/actions?workflow=Compile+Examples)
+[![Arduino Lint](https://github.com/arduino-libraries/Arduino_Portenta_OTA/workflows/Arduino%20Lint/badge.svg)](https://github.com/arduino-libraries/Arduino_Portenta_OTA/actions?workflow=Arduino+Lint)
 [![Spell Check](https://github.com/arduino-libraries/Arduino_Portenta_OTA/workflows/Spell%20Check/badge.svg)](https://github.com/arduino-libraries/Arduino_Portenta_OTA/actions?workflow=Spell+Check)
 
 OTA on the Arduino Portenta.