Add pre-commit hook / linter (#229)

Author: jarrodmillman

.github/workflows/lint.yml

@@ -0,0 +1,26 @@
+name: style
+
+on: [push, pull_request]
+
+jobs:
+  format:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [3.9]
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install packages
+        run: |
+          pip install --upgrade pip
+          pip install -r requirements.txt
+
+      - name: Lint
+        run: pre-commit run --all-files --show-diff-on-failure --color always

.pre-commit-config.yaml

@@ -0,0 +1,15 @@
+# Install pre-commit hooks via
+# pre-commit install
+
+repos:
+  - repo: https://github.com/psf/black
+    rev: 22.1.0
+    hooks:
+      - id: black
+
+  - repo: https://github.com/pre-commit/mirrors-prettier
+    rev: v2.6.0
+    hooks:
+      - id: prettier
+        files: \.(md|yml|yaml)
+        args: [--prose-wrap=preserve]

requirements.txt

@@ -0,0 +1 @@
+pre-commit>=2.17