Problems with "Running Benchmarks Locally" instructions

[Mark Bolusmjak]

Hey Matt and team. I tried Running Benchmarks locally.
First, instructions assume tsc is already installed. (Easy fix).
Second problem is tsconfig.json is too restrictive to allow successful compilation. The following loosening of restrictions permits compilation:

-    "noUnusedLocals": true,
-    "noUnusedParameters": true,
+    "noUnusedLocals": false,
+    "noUnusedParameters": false

Next, is an error with terser. I'm not clear on the fix here:

Error compressing with Terser
Error mangling with Terser                                                                                                                   Error compressing with Terser                                                                                                                Error mangling with Terser                                                                                                                   Error: ENOENT: no such file or directory, open 'testcases/html/output/elm.opt.min.js'                                                        Error: ENOENT: no such file or directory, open 'testcases/html/output/elm.opt.min.js'
...
RuntimeError: abort(Error: ENOENT: no such file or directory, open 'testcases/html/output/elm.opt.min.js'). Build with -s ASSERTIONS=1 for more info.
    at process.abort (/Users/mark/work/elm-optimize-level-2/node_modules/@gfx/zopfli/dist/libzopfli.js:1:11690)
    at process.emit (node:events:369:20)
    at process.emit (node:domain:470:12)
    at process.emit (/Users/mark/work/elm-optimize-level-2/node_modules/source-map-support/source-map-support.js:495:21)
    at emit (node:internal/process/promises:135:22)
    at processPromiseRejections (node:internal/process/promises:241:25)
    at processTicksAndRejections (node:internal/process/task_queues:95:32)