ci: set up reusable _lint workflow (rdmorganiser#13)

Fixes rdmorganiser#9

.github/workflows/_lint.yml

@@ -0,0 +1,33 @@
+# This is a reusable workflow.
+#
+# Usage: Use the workflow in calling workflows like this:
+# "uses: rdmorganiser/.github/.github/workflows/_lint.yml@main"
+# Pin it to a branch, tag or commit hash.
+#
+# Ref: https://docs.github.com/en/actions/using-workflows/reusing-workflows
+
+name: Lint
+
+on:
+  workflow_call: # reusable workflow
+
+permissions: {} # Set permissions at the job level
+
+env:
+  PYTHONDONTWRITEBYTECODE: 1
+  FORCE_COLOR: 1 # enforce colored output
+
+jobs:
+
+  lint:
+    name: Lint
+    runs-on: ubuntu-24.04
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
+    - name: Run linters via pre-commit (e.g. typos)
+      uses: pre-commit/action@2c7b3805fd2a0fd8c1884dcaebf91fc102a13ecd # v3.0.1
+      with:
+        extra_args: --all-files --color=always

.github/workflows/ci.yml

@@ -0,0 +1,19 @@
+name: Lint
+
+on:
+  push:
+    branches:
+    - main
+  pull_request:
+  workflow_dispatch: # run manually from actions tab
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions: {} # Set permissions at the job level
+
+jobs:
+
+  lint:
+    uses: ./.github/workflows/_lint.yml

.pre-commit-config.yaml

@@ -0,0 +1,38 @@
+# pre-commit
+# Ref: https://pre-commit.com/#usage
+# More hooks: https://pre-commit.com/hooks.html
+# ------------------------------------------------------------------------------
+
+repos:
+
+- repo: meta
+  hooks:
+  - id: check-hooks-apply
+
+  # Check all files for generic issues, e.g. trailing whitespace
+- repo: https://github.com/pre-commit/pre-commit-hooks
+  rev: v4.6.0
+  hooks:
+  - id: check-yaml
+  - id: end-of-file-fixer
+  - id: trailing-whitespace
+
+  # Pretty-format YAML files
+- repo: https://github.com/macisamuele/language-formatters-pre-commit-hooks
+  rev: v2.13.0
+  hooks:
+  - id: pretty-format-yaml
+    args: [--autofix, --indent, '2']
+
+  # Check JSON Schema
+- repo: https://github.com/python-jsonschema/check-jsonschema
+  rev: 0.29.0
+  hooks:
+  - id: check-dependabot
+  - id: check-github-workflows
+
+  # Check for typos
+- repo: https://github.com/crate-ci/typos
+  rev: v1.23.2
+  hooks:
+  - id: typos