ci: add codeowners and checks

.github/CODEOWNERS

@@ -0,0 +1,15 @@
+# Any change to files in the root directory, any later match takes precedence.
+* @NTBBloodbath @vhyrro @mrcjkb
+
+# Documentation
+*.md @NTBBloodbath @vhyrro @mrcjkb
+doc/ @NTBBloodbath @vhyrro @mrcjkb
+
+# Plugin files
+lua/ @NTBBloodbath @vhyrro @mrcjkb
+spec/ @NTBBloodbath @vhyrro @mrcjkb
+plugin/ @NTBBloodbath @vhyrro @mrcjkb
+
+# Nix
+nix/ @mrcjkb @teto
+flake.* @mrcjkb @teto

.github/workflows/checks.yaml

@@ -0,0 +1,26 @@
+---
+name: "Checks"
+on:
+  pull_request:
+  push:
+  workflow_call:
+jobs:
+  checks:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - uses: cachix/install-nix-action@v22
+      with:
+        name: neorocks
+        authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+    - run: nix flake check -L --accept-flake-config
+  shell:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - uses: cachix/install-nix-action@v22
+    - uses: cachix/cachix-action@v12
+      with:
+        name: neorocks
+        authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+    - run: nix build .#devShells.x86_64-linux.default -L --accept-flake-config