ci: add release workflow to publish new tags to LuaRocks

NOTE: This requires a LUAROCKS_API_KEY.
See the
[luarocks-tag-release readme](https://github.com/nvim-neorocks/luarocks-tag-release#prerequisites)

.github/workflows/release.yaml

@@ -0,0 +1,23 @@
+name: "release"
+on:
+  push:
+    tags:
+      - 'v*'
+jobs:
+  luarocks-upload:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v3
+      - name: LuaRocks Upload
+        uses: nvim-neorocks/luarocks-tag-release@v2.0.0
+        env:
+          LUAROCKS_API_KEY: ${{ secrets.LUAROCKS_API_KEY }}
+        with:
+          detailed_description: |
+            A completion engine plugin for neovim written in Lua.
+            Completion sources are installed from external repositories and "sourced".
+          copy_directories:
+            autoload
+            plugin
+            doc
+

nvim-cmp-scm-1.rockspec

@@ -18,16 +18,9 @@ dependencies = {
 }
 
 source = {
-  url = 'http://github.com/hrsh7th/nvim-cmp/archive/v' .. MODREV .. '.zip',
-  dir = 'nvim-cmp-' .. MODREV,
+  url = 'git://github.com/hrsh7th/nvim-cmp',
 }
 
-if MODREV == 'scm' then
-  source = {
-    url = 'git://github.com/hrsh7th/nvim-cmp',
-  }
-end
-
 build = {
   type = 'builtin',
   copy_directories = {