Add onboard project count

pages/api/onboard/project-count.js

@@ -0,0 +1,16 @@
+async function onboardProjectCount() {
+  const url = 'https://api.github.com/repos/hackclub/onboard/contents/projects'
+
+  const response = await fetch(url).then(r => r.json())
+  const countedProjects = response.filter(
+    folder =>
+      folder.type === 'dir' && folder.name[0] !== '.' && folder.name[0] !== '!'
+  )
+  return countedProjects.length
+}
+
+export default async function handler(req, res) {
+  const count = await onboardProjectCount()
+
+  res.json({ count })
+}