nvim: Change markdown_preview build process

nvim/.config/nvim/lua/plugins/markdown_preview.lua

@@ -1,15 +1,27 @@
 return {
-    {
-        "iamcco/markdown-preview.nvim",
-        cmd = {
-            "MarkdownPreviewToggle",
-            "MarkdownPreview",
-            "MarkdownPreviewStop"
-        },
-        ft = {
-            "markdown"
-        },
-        build = function() vim.fn["mkdp#util#install"]() end
-    }
-
+    -- Install markdown preview, use npx if available.
+    "iamcco/markdown-preview.nvim",
+    cmd = {
+        "MarkdownPreviewToggle",
+        "MarkdownPreview",
+        "MarkdownPreviewStop"
+    },
+    ft = {
+        "markdown"
+    },
+    build = function(plugin)
+        if vim.fn.executable "npx" then
+            vim.cmd("!cd " .. plugin.dir .. " && cd app && npx --yes yarn install")
+        else
+            vim.cmd [[Lazy load markdown-preview.nvim]]
+            vim.fn["mkdp#util#install"]()
+        end
+    end,
+    init = function()
+        if vim.fn.executable "npx" then
+            vim.g.mkdp_filetypes = {
+                "markdown"
+            }
+        end
+    end
 }