[chore] format code and fix lint issues

[Neet-Nestor]

This PR formats the entire repo and fixes or suppresses all lint issues by running the following commands:

• npm run format
• npm run lint

Testing

 $ npm test    

> @mlc-ai/[email protected] test
> yarn jest

yarn run v1.22.22
$ /Users/neet/code/web-llm/node_modules/.bin/jest
jest-haste-map: Haste module naming collision: chrome-extension
  The following files share their name; please adjust your hasteImpl:
    * <rootDir>/examples/chrome-extension/package.json
    * <rootDir>/examples/chrome-extension-webgpu-service-worker/package.json

jest-haste-map: Haste module naming collision: openai-api
  The following files share their name; please adjust your hasteImpl:
    * <rootDir>/examples/function-calling/package.json
    * <rootDir>/examples/json-mode/package.json

jest-haste-map: Haste module naming collision: simple-chat
  The following files share their name; please adjust your hasteImpl:
    * <rootDir>/examples/simple-chat-ts/package.json
    * <rootDir>/examples/simple-chat-upload/package.json

 PASS  tests/util.test.ts
 PASS  tests/openai_chat_completion.test.ts
 PASS  tests/generation_config.test.ts
  ● Console

    console.warn
      Only frequency_penalty is set; we default presence_penaty to 0.

      183 |   ) {
      184 |     config.presence_penalty = 0.0;
    > 185 |     log.warn("Only frequency_penalty is set; we default presence_penaty to 0.");
          |         ^
      186 |   }
      187 |   if (
      188 |     _hasValue(config.presence_penalty) &&

      at postInitAndCheckGenerationConfigValues (src/config.ts:185:9)
      at Object.<anonymous> (tests/generation_config.test.ts:79:43)

 PASS  tests/conv_template.test.ts
  ● Console

    console.log
      [INST] <<SYS>>
      You are a helpful, respectful and honest assistant.
      <</SYS>>
      
       test1 [/INST] test2 [INST] test3 [/INST]

      at Object.<anonymous> (tests/conv_template.test.ts:114:13)

 PASS  tests/multi_round_chat.test.ts
 PASS  tests/function_calling.test.ts

Test Suites: 6 passed, 6 total
Tests:       33 passed, 33 total
Snapshots:   0 total
Time:        1.84 s
Ran all test suites.
✨  Done in 2.97s.

npm run build 

> @mlc-ai/[email protected] build
> rollup -c && ./cleanup-index-js.sh


src/index.ts → lib/index.js...
created lib/index.js in 1.4s

[CharlieFRuan]

Thank you so much!