Fixed doctest

.github/workflows/rust.yml

@@ -0,0 +1,26 @@
+name: Rust
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Build
+      run: cargo build --verbose
+    - name: Run tests
+      run: cargo test --verbose
+    - name: Clippy
+      run: cargo clippy
+    - name: Formatting
+      run: cargo fmt --check

rust-toolchain.toml

@@ -1,2 +1,2 @@
 [toolchain]
-channel = "nightly"
+channel = "stable"