feat(pack): add Rego language pack (#931)

lua/astrocommunity/pack/rego/README.md

@@ -0,0 +1,7 @@
+# OPA Rego Pack
+
+This plugin pack does the following:
+
+- Adds `rego` Treesitter parser
+- Adds `regols` language server
+- Adds `opacheck` linter

lua/astrocommunity/pack/rego/init.lua

@@ -0,0 +1,47 @@
+return {
+  {
+    "nvim-treesitter/nvim-treesitter",
+    optional = true,
+    opts = function(_, opts)
+      if opts.ensure_installed ~= "all" then
+        opts.ensure_installed = require("astrocore").list_insert_unique(opts.ensure_installed, { "rego" })
+      end
+    end,
+  },
+  {
+    "williamboman/mason-lspconfig.nvim",
+    optional = true,
+    opts = function(_, opts)
+      opts.ensure_installed = require("astrocore").list_insert_unique(opts.ensure_installed, { "regols" })
+    end,
+  },
+  {
+    "nvimtools/none-ls.nvim",
+    optional = true,
+    opts = function(_, opts)
+      if vim.fn.executable "opa" == 1 then
+        local nls = require "null-ls"
+        if not opts.sources then opts.sources = {} end
+        opts.sources = vim.list_extend(opts.sources, {
+          nls.builtins.diagnostics.opacheck,
+        })
+      end
+    end,
+  },
+  {
+    "WhoIsSethDaniel/mason-tool-installer.nvim",
+    optional = true,
+    opts = function(_, opts)
+      opts.ensure_installed = require("astrocore").list_insert_unique(opts.ensure_installed, { "regols" })
+    end,
+  },
+  {
+    "mfussenegger/nvim-lint",
+    optional = true,
+    opts = {
+      linters_by_ft = {
+        rego = { "opa_check" },
+      },
+    },
+  },
+}