fix: add 404 page

Author: seveibar

src/router.js

@@ -1,3 +1,4 @@
+const micro = require("micro")
 const { router, get, post, patch, options } = require("microrouter")
 
 const getDiffsEndpoint = require("./endpoints/get-diffs.js")
@@ -8,6 +9,8 @@ const getSampleEndpoint = require("./endpoints/get-sample.js")
 const patchSampleEndpoint = require("./endpoints/patch-sample.js")
 const downloadEndpoint = require("./endpoints/download-session.js")
 
+const notfound = (req, res) => micro.send(res, 404)
+
 module.exports = router(
   post("/api/session", postSessionEndpoint),
   options("/api/session", postSessionEndpoint),
@@ -18,5 +21,6 @@ module.exports = router(
   patch("/api/session/:session_id/sample/:sample_index", patchSampleEndpoint),
   get("/api/session/:session_id", getSessionEndpoint),
   patch("/api/session/:session_id", patchSessionEndpoint),
-  options("/api/session/:session_id", patchSessionEndpoint)
+  options("/api/session/:session_id", patchSessionEndpoint),
+  get("/*", notfound)
 )