Add CI workflow to check for commonly misspelled words

On every push, pull request, and periodically, use the codespell-project/actions-codespell action to check for commonly
misspelled words.

In the event of a false positive, the problematic word should be added, in all lowercase, to the ignore-words-list field
of ./.codespellrc. Regardless of the case of the word in the false positive, it must be in all lowercase in the ignore
list. The ignore list is comma-separated with no spaces.

Author: per1234

.codespellrc

@@ -0,0 +1,7 @@
+# See: https://github.com/codespell-project/codespell#using-a-config-file
+[codespell]
+# In the event of a false positive, add the problematic word, in all lowercase, to a comma-separated list here:
+ignore-words-list = ,
+check-filenames =
+check-hidden =
+skip = ./.git,./extras/D11-Firmware/src,./src/src

.github/workflows/spell-check.yml

@@ -0,0 +1,22 @@
+name: Spell Check
+
+# See: https://docs.github.com/en/free-pro-team@latest/actions/reference/events-that-trigger-workflows
+on:
+  push:
+  pull_request:
+  schedule:
+    # Run every Tuesday at 8 AM UTC to catch new misspelling detections resulting from dictionary updates.
+    - cron: "0 8 * * TUE"
+  workflow_dispatch:
+  repository_dispatch:
+
+jobs:
+  spellcheck:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Spell check
+        uses: codespell-project/actions-codespell@master

README.md

@@ -1,5 +1,6 @@
 # MKRMotorCarrier library
 
+[![Spell Check status](https://github.com/arduino-libraries/ArduinoMotorCarrier/actions/workflows/spell-check.yml/badge.svg)](https://github.com/arduino-libraries/ArduinoMotorCarrier/actions/workflows/spell-check.yml)
 
 This library is designed to use the MKR Motor carrier. The shield supports micro servo motors, dc motors and dc motors with encoder. This library, therefore, has functions and creates objects to support such hardware. Objects are automatically created when "ArduinoMotorCarrier.h" is included, hence no need to initiate objects manually.