add github actions from gentoo/kde

I saw this land and thought it might be neat.  I have no idea if it will
work for us but I'm interesting in trying.

.github/workflows/README

@@ -0,0 +1,2 @@
+This work was taken from https://github.com/gentoo/kde/tree/master/.github/workflows
+Original work from Alfred Wingate https://github.com/parona-source

.github/workflows/pkgcheck.yaml

@@ -0,0 +1,13 @@
+name: pkgcheck
+on:
+  push:
+    branches: [master]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: Run pkgcheck
+        uses: pkgcore/pkgcheck-action@v1

.github/workflows/pkgcheck_merge.yaml

@@ -0,0 +1,17 @@
+name: pkgcheck_merge
+on:
+  pull_request:
+    branches: [master]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 2
+      - name: Run pkgcheck
+        uses: pkgcore/pkgcheck-action@v1
+        with:
+          args: --exit warning --commits HEAD^..${{ github.sha }}