Add super-linter

.github/linters/.codespellrc

@@ -0,0 +1,9 @@
+[codespell]
+# Binary and generated files produce nothing but noise: codespell reads PDFs
+# as text and lockfiles are full of package names that look like typos.
+skip = *.pdf,*.lock,*.min.js,*.min.css,*.svg,*.png,*.jpg,*.ico,./node_modules,./.git,./dist,./build,pnpm-lock.yaml,package-lock.json,uv.lock,go.sum
+# coo        — Chief Operating Officer
+# pres       — slide/presentation identifier, not "press"
+# unparseable— an accepted spelling
+# lifes      — "still lifes" is the Conway's Game of Life term of art
+ignore-words-list = coo,pres,unparseable,lifes

.github/linters/.htmlhintrc

@@ -0,0 +1,14 @@
+{
+  "tagname-lowercase": true,
+  "attr-lowercase": true,
+  "attr-value-double-quotes": true,
+  "tag-pair": true,
+  "spec-char-escape": true,
+  "id-unique": true,
+  "src-not-empty": true,
+  "attr-no-duplication": true,
+  "title-require": true,
+  "_comment": "doctype-first is off because Jinja partials are fragments, not documents. id-class-value is off because camelCase ids are standard in JS-driven pages and are queried by name from script.",
+  "doctype-first": false,
+  "id-class-value": false
+}

.github/linters/.markdown-lint.yml

@@ -0,0 +1,6 @@
+---
+# Hard-wrapping prose at a fixed column is a style most markdown tooling has
+# moved on from.
+MD013: false
+# A README that opens with a sentence rather than a title is fine.
+MD041: false

.github/workflows/linter.yml

@@ -0,0 +1,55 @@
+---
+name: Lint
+
+on: # yamllint disable-line rule:truthy
+  push:
+  pull_request:
+
+permissions: {}
+
+jobs:
+  build:
+    name: Lint
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      packages: read
+      statuses: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          # zizmor/artipacked: keep the token out of .git/config; this job
+          # only reads the tree, it never pushes.
+          persist-credentials: false
+          # super-linter diffs against the base, so it needs full history.
+          fetch-depth: 0
+
+      - name: Super-linter
+        uses: super-linter/super-linter@4ce20838b8ab83717e78138c5b3a1407148e0918 # v8.7.0
+        env:
+          VALIDATE_ALL_CODEBASE: true
+          DEFAULT_BRANCH: main
+          # Terminology rules fight the prose in these repos more than they help.
+          VALIDATE_NATURAL_LANGUAGE: false
+          # Flags intentional repetition (generated files, repeated markup) far more
+          # often than real duplication.
+          VALIDATE_JSCPD: false
+          # biome and prettier disagree on indentation (tabs vs spaces) and both
+          # run on the same files, so no formatting satisfies both. prettier wins
+          # here because it covers more file types; BIOME_LINT stays on.
+          VALIDATE_BIOME_FORMAT: false
+          # stylelint and biome both lint CSS with different opinions. biome is the
+          # more widely used of the two and also covers js/ts, so it is the one kept.
+          VALIDATE_CSS: false
+          # black and ruff format disagree on assert-message wrapping, and both
+          # run here. ruff is the more widely used of the two and its formatter
+          # is >99.9% black-compatible, so ruff format is the authority.
+          VALIDATE_PYTHON_BLACK: false
+          # super-linter warns that biome and eslint both lint JSON and may
+          # conflict. biome is the one kept, per the same call made for CSS.
+          VALIDATE_JSON: false
+          VALIDATE_JSONC: false
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

README.md

@@ -1,7 +1,9 @@
 # strangerduino
+
 Stranger Things Christmas Lights Communicator
 
 ## Description
+
 Built for a family member's Halloween display, this allows for displaying arbitrary "words" as highlighted by an appropriately numbered LED light, as well as a randomized "Christmas" mode.
 
 This assumes a LED light string supported by the [FastLED](https://fastled.io/) library.