ci: enable lint on pr from forks

Per comment https://github.com/badgen/badgen.net/pull/453#issuecomment-743983653

.github/workflows/nodejs.yml

@@ -1,6 +1,10 @@
 name: lint and build
 
-on: [push]
+on:
+  push:
+  pull_request:
+    branches:
+    - '**:**'
 
 jobs:
   build:
@@ -8,10 +12,10 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - uses: actions/setup-node@v1
       with:
-        node-version: '12.x'
+        node-version: '12'
     - name: npm install, build, and test
       run: |
         npm ci