refactor: move into npm workspace

Author: ascorbic

.nvmrc

@@ -0,0 +1 @@
+17.9.0

demos/default/local-plugin/index.js

@@ -1,7 +1,7 @@
 [build]
 command = "next build"
 publish = ".next"
-ignore = "git diff --quiet $CACHED_COMMIT_REF $COMMIT_REF ../../"
+ignore = "git diff --quiet $CACHED_COMMIT_REF $COMMIT_REF . ../../plugin"
 
 [build.environment]
 # cache Cypress binary in local "node_modules" folder
@@ -14,7 +14,4 @@ TERM = "xterm"
 framework = "#static"
 
 [[plugins]]
-package = "./local-plugin"
-
-[[plugins]]
-package = "@netlify/plugin-local-install-core"
+package = "../../plugin"

demos/default/local-plugin/manifest.yml

@@ -0,0 +1,26 @@
+{
+  "name": "default-demo",
+  "version": "1.0.0",
+  "private": true,
+  "description": "",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/netlify/netlify-plugin-nextjs.git"
+  },
+  "author": "",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/netlify/netlify-plugin-nextjs/issues"
+  },
+  "homepage": "https://github.com/netlify/netlify-plugin-nextjs#readme",
+  "dependencies": {
+    "@reach/dialog": "^0.16.2",
+    "@reach/visually-hidden": "^0.16.0"
+  },
+  "devDependencies": {
+    "@netlify/plugin-nextjs": "*"
+  }
+}