update(yargs-parser): updates the yargs-parser dependency (#2326)

As of `v19`, `yargs-parser` is now shipping its own types.

The types seem to be working fairly well in our codebase, with the hiccup that one type was corrected, `_` can be a number or string.

```
node example.mjs apple 99 batman
{ _: [ 'apple', 99, 'batman' ] }
```

FYI, `yargs-parser` now supports ESM:

```js
import parser from 'yargs-parser'

console.info(parser(process.argv.slice(2)))
```

**and Deno 😮**

```typescript
import parser from "https://deno.land/x/yargs_parser/deno.ts";

const argv = parser('--foo=99 --bar=9987930', {
  string: ['bar']
})
console.log(argv)
```

package.json

@@ -54,6 +54,8 @@
   },
   "devDependencies": {
     "@compodoc/compodoc": "^1.1.10",
+    "@microsoft/api-documenter": "^7.8.10",
+    "@microsoft/api-extractor": "^7.8.10",
     "@types/execa": "^0.9.0",
     "@types/mkdirp": "^1.0.0",
     "@types/mocha": "^8.0.0",
@@ -67,7 +69,6 @@
     "@types/sinon": "^9.0.0",
     "@types/tmp": "^0.2.0",
     "@types/url-template": "^2.0.28",
-    "@types/yargs-parser": "^15.0.0",
     "c8": "^7.0.0",
     "codecov": "^3.4.0",
     "execa": "^4.0.0",
@@ -89,8 +90,6 @@
     "sinon": "^9.0.2",
     "tmp": "^0.2.0",
     "typescript": "^3.8.3",
-    "yargs-parser": "^18.1.3",
-    "@microsoft/api-documenter": "^7.8.10",
-    "@microsoft/api-extractor": "^7.8.10"
+    "yargs-parser": "^19.0.1"
   }
 }

src/generator/generator.ts

@@ -276,7 +276,7 @@ async function main() {
   if (!discoveryUrl && argv._.length > 0) {
     argv._.forEach(async url => {
       console.log(`Generating API for ${url}`);
-      await gen.generateAPI(url);
+      await gen.generateAPI('' + url);
       console.log('Generated API for ' + url);
     });
   } else {