ci: add GitHub workflows and issue templates

Problem: need CI for tests, quality checks, luarocks publishing,
and structured issue/discussion templates.

Solution: add test, quality, and luarocks workflows mirroring
diffs.nvim conventions. Add bug report, feature request, and
Q&A templates.

.github/workflows/test.yaml

@@ -0,0 +1,22 @@
+name: test
+
+on:
+  pull_request:
+    branches: [main]
+  push:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        nvim: [stable, nightly]
+    name: Test (Neovim ${{ matrix.nvim }})
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: nvim-neorocks/nvim-busted-action@v1
+        with:
+          nvim_version: ${{ matrix.nvim }}