Add "smoke test" examples compilation CI workflow

On every push or pull request that affects library source or example files, and periodically, compile all example
sketches for the specified boards.

Author: per1234

.github/workflows/compile-examples.yml

@@ -1,20 +1,55 @@
 name: Compile Examples
-on: [push, pull_request]
+
+# See: https://docs.github.com/en/free-pro-team@latest/actions/reference/events-that-trigger-workflows
+on:
+  push:
+    paths:
+      - ".github/workflows/compile-examples.yml"
+      - "examples/**"
+      - "src/**"
+  pull_request:
+    paths:
+      - ".github/workflows/compile-examples.yml"
+      - "examples/**"
+      - "src/**"
+  schedule:
+    # Run every Tuesday at 8 AM UTC to catch breakage caused by changes to external resources (libraries, platforms).
+    - cron: "0 8 * * TUE"
+  workflow_dispatch:
+  repository_dispatch:
+
 jobs:
- build:
-   runs-on: ubuntu-latest
+  build:
+    name: ${{ matrix.board.fqbn }}
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+
+      matrix:
+        board:
+          - fqbn: arduino:megaavr:uno2018
+            platforms: |
+              - name: arduino:megaavr
+          - fqbn: arduino:samd:nano_33_iot
+            platforms: |
+              - name: arduino:samd
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
 
-   strategy:
-     matrix:
-       fqbn: [
-         "arduino:megaavr:uno2018:mode=on",
-         "arduino:samd:nano_33_iot"
-       ]
+      - name: Compile examples
+        uses: arduino/compile-sketches@v1
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          fqbn: ${{ matrix.board.fqbn }}
+          platforms: ${{ matrix.board.platforms }}
+          libraries: |
+            # Install the library from the local path.
+            - source-path: ./
+            # Additional library dependencies can be listed here.
+            # See: https://github.com/arduino/compile-sketches#libraries
+          sketch-paths: |
+            - examples
 
-   steps:
-     - uses: actions/checkout@v1
-       with:
-         fetch-depth: 1
-     - uses: arduino/actions/libraries/compile-examples@master
-       with:
-         fqbn: ${{ matrix.fqbn }}

README.adoc

@@ -4,6 +4,7 @@
 = {repository-name} Library for Arduino =
 
 image:https://github.com/{repository-owner}/{repository-name}/actions/workflows/check-arduino.yml/badge.svg["Check Arduino status", link="https://github.com/{repository-owner}/{repository-name}/actions/workflows/check-arduino.yml"]
+image:https://github.com/{repository-owner}/{repository-name}/actions/workflows/compile-examples.yml/badge.svg["Compile Examples status", link="https://github.com/{repository-owner}/{repository-name}/actions/workflows/compile-examples.yml"]
 image:https://github.com/{repository-owner}/{repository-name}/actions/workflows/spell-check.yml/badge.svg["Spell Check status", link="https://github.com/{repository-owner}/{repository-name}/actions/workflows/spell-check.yml"]
 
 Allows you to read the accelerometer and gyroscope values from the LSM6DS3 IMU on your Arduino Nano 33 IoT or Arduino Uno WiFi Rev2 boards.