diff --git a/.github/workflows/ghc.yml b/.github/workflows/ghc.yml
index 9b8b86911..29c358bfe 100644
--- a/.github/workflows/ghc.yml
+++ b/.github/workflows/ghc.yml
@@ -23,11 +23,16 @@
 name: GHC (build, test, haddock)
 
 # Controls when the workflow will run
-on:
+'on':
   push:
-    branches: [master]
+    branches:
+      - master
     tags: [v*]
+    paths-ignore: [ 'README.md' ]
   pull_request:
+    branches:
+      - master
+    paths-ignore: [ 'README.md' ]
 
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch:
diff --git a/.github/workflows/markdown-lint.yml b/.github/workflows/markdown-lint.yml
new file mode 100644
index 000000000..52f0499da
--- /dev/null
+++ b/.github/workflows/markdown-lint.yml
@@ -0,0 +1,38 @@
+# The MIT License (MIT)
+#
+# Copyright (c) 2016-2024 Objectionary.com
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+---
+name: markdown-lint
+'on':
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+jobs:
+  markdown-lint:
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: articulate/actions-markdownlint@v1
+        with:
+          files: 'README.md'
diff --git a/README.md b/README.md
index 79007cb91..f711039c9 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,54 @@
 [![Hits-of-Code](https://hitsofcode.com/github/objectionary/eo-phi-normalizer?branch=master&label=Hits-of-Code)](https://hitsofcode.com/github/objectionary/eo-phi-normalizer/view?branch=master&label=Hits-of-Code)
 ![Lines of code](https://sloc.xyz/github/objectionary/eo-phi-normalizer)
 
-Command line normalizer of 𝜑-calculus expressions (as produced by the [EO compiler](https://github.com/objectionary/eo)).
+This command line tool helps you deal with 𝜑-calculus expressions, usually
+produced by the [EO compiler][eo].
 
-Consult the [project documentation](https://www.objectionary.com/eo-phi-normalizer/) for more details.
+First, install it (you should install [Stack][stack] first):
+
+```bash
+stack update
+stack install eo-phi-normalizer
+```
+
+Then, normalize a simple 𝜑-expression:
+
+```bash
+$ cat > foo.phi
+{⟦ m ↦ ⟦ x ↦ ⟦ ρ ↦ ∅ ⟧.ρ.k, k ↦ ⟦ Δ ⤍ 42- ⟧ ⟧.x ⟧}
+$ eo-phi-normalizer rewrite --chain --tex foo.phi
+```
+
+The output will contain a ready-to-use LaTeX document, where all
+rewritting steps are explained.
+
+More detailed documentation is [here][site].
+
+## How to use custom rules?
+
+By default, the rules of normalization of 𝜑-calculus are used. They are
+defined in the [rules.yaml][rules] file. You can use your own rules, with the
+help of our custom YAML format, for example in `forty-three.yml`:
+
+```yaml
+title: "forty-three"
+rules:
+  - name: forty-three
+    description: 'change 33 double to 42 double'
+    pattern: |
+      Φ.org.eolang.bytes ( α0 ↦ ⟦ Δ ⤍ 40-40-80-00-00-00-00-00 ⟧ )
+    result: |
+      Φ.org.eolang.bytes ( α0 ↦ ⟦ Δ ⤍ 40-45-00-00-00-00-00-00 ⟧ )
+    tests: [ ]
+```
+
+Then, use this file:
+
+```bash
+eo-phi-normalizer rewrite --rules=forty-three.yml foo.phi
+```
+
+[site]: https://www.objectionary.com/eo-phi-normalizer/
+[stack]: https://docs.haskellstack.org/en/stable/install_and_upgrade/
+[eo]: https://github.com/objectionary/eo
+[rules]: https://github.com/objectionary/eo-phi-normalizer/blob/master/eo-phi-normalizer/test/eo/phi/rules/new.yaml