Use vercel/ncc

`nc build index.js --license licenses.txt` compiles our code and all the
modules into a single file (`dist/index.js``). This has to be done and
the resulting files updated before any release.

action.yml

@@ -22,4 +22,4 @@ inputs:
     default: 'm.notice'
 runs:
   using: 'node12'
-  main: 'index.js'
+  main: 'dist/index.js'

package-lock.json

@@ -195,6 +195,11 @@
       "resolved": "https://registry.npmjs.org/@types/node/-/node-14.11.2.tgz",
       "integrity": "sha512-jiE3QIxJ8JLNcb1Ps6rDbysDhN4xa8DJJvuC9prr6w+1tIh+QAbYyNF3tyiZNLDBIuBCf4KEcV2UvQm/V60xfA=="
     },
+    "@vercel/ncc": {
+      "version": "0.24.1",
+      "resolved": "https://registry.npmjs.org/@vercel/ncc/-/ncc-0.24.1.tgz",
+      "integrity": "sha512-r9m7brz2hNmq5TF3sxrK4qR/FhXn44XIMglQUir4sT7Sh5GOaYXlMYikHFwJStf8rmQGTlvOoBXt4yHVonRG8A=="
+    },
     "acorn": {
       "version": "7.4.1",
       "resolved": "https://registry.npmjs.org/acorn/-/acorn-7.4.1.tgz",

package.json

@@ -19,6 +19,7 @@
   "dependencies": {
     "@actions/core": "^1.2.6",
     "@actions/github": "^4.0.0",
+    "@vercel/ncc": "^0.24.1",
     "matrix-js-sdk": "^8.4.1"
   },
   "devDependencies": {