Add workflow to check all flakes.

Author: IogaMaster

.github/scripts/check.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+find . -type d -maxdepth 1 \( -iname "*" ! -iname ".*" \) | while read line; do
+    pushd $line
+    nix flake check || { echo 'Check Failed!' ; exit 1; }
+    popd
+done

.github/workflows/check.yml

@@ -0,0 +1,12 @@
+name: "Check"
+on:
+  pull_request:
+  push:
+
+jobs:
+  check-flakes:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - uses: cachix/install-nix-action@v20
+    - run: ./.github/scripts/check.sh