replace prettier-check with autofix, update readme

.github/workflows/autofix.yml

@@ -0,0 +1,26 @@
+name: autofix.ci # needed to securely identify the workflow
+
+on:
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  autofix:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version-file: ".nvmrc"
+      - name: Install dependencies
+        run: pnpm install
+      - name: Fix formatting
+        run: pnpm run fmt
+      - name: Apply fixes
+        uses: autofix-ci/action@dd55f44df8f7cdb7a6bf74c78677eb8acd40cd0a
+        with:
+          commit-message: 'ci: apply automated fixes'

README.md

@@ -18,6 +18,16 @@ Prerequisites required:
 
 We use [direnv](https://direnv.net/) to assist you with setting up all of the required tooling.
 
+<details>
+  <summary>Prefer to install and manage the tooling yourself?</summary>
+
+1. Install [nvm](https://github.com/nvm-sh/nvm?tab=readme-ov-file#installing-and-updating) or your node version manager of choice.
+2. Ensure that `node 20` is installed. With `nvm`, run `nvm install`.
+3. Enable `pnpm` with `corepack`: `corepack enable pnpm`
+4. Install `pnpm` with `corepack`: `corepack install`
+5. Install project dependencies with `pnpm`: `pnpm install`
+</details>
+
 First, install `direnv`:
 
 | OS     | command                 |
@@ -27,6 +37,8 @@ First, install `direnv`:
 
 For all other OSes, see the [direnv installation guide](https://direnv.net/docs/installation.html).
 
+Don't forget to [set up direnv integration with your shell](https://direnv.net/docs/hook.html).
+
 Next, clone the repo and move into the directory:
 
 ```sh