Check readme in pipeline

Author: eivindbergem

.github/workflows/rust.yml

@@ -10,6 +10,23 @@ env:
   CARGO_TERM_COLOR: always
 
 jobs:
+  readme:
+    runs-on: ubuntu-latest
+
+    defaults:
+      run:
+        working-directory: ./hyperloop
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/install@v0.1
+        with:
+          crate: cargo-readme
+          version: latest
+          use-tool-cache: true
+      - name: Readme
+        run: cargo readme > ../README.md && git diff --exit-code
+
   format:
     runs-on: ubuntu-latest