concat documentation not showing up on rxjs.dev

### Describe the bug

Some awesome documentation exists in the file [`src/internal/observable/concat.ts`](https://github.com/ReactiveX/rxjs/blob/master/src/internal/observable/concat.ts) as JSDoc.



However, it's not present on [rxjs.dev](https://rxjs.dev/api/index/function/concat).



What it currently looks like:

<img width="637" alt="image" src="https://user-images.githubusercontent.com/22200293/177014592-00024d38-9ce6-4646-a6be-4821faedbd68.png">





### Expected behavior

I expect the documentation to show up on [rxjs.dev](https://rxjs.dev/api/index/function/concat).



It would look like this:



<img width="637" alt="image" src="https://user-images.githubusercontent.com/22200293/177014617-15ecc933-7338-4974-884d-0e1692b15e6b.png">



### Reproduction code

```typescript
# Non-local: 

- Go to: https://rxjs.dev/api/index/function/concat



# Local:

- cd docs_app

- npm run docs

- npm run start

- Go to: http://localhost:4200/api/index/function/concat
```


### Reproduction URL

https://rxjs.dev/api/index/function/concat

### Version

7.5.5

### Environment

_No response_

### Additional context

I have narrowed the problem down to the TypeScript package in [dgeni-packages](https://github.com/angular/dgeni-packages#typescript-package).



It produces wrong information about the function overloads. I should probably open an issue there, but I want to know what you think about this first. Maybe I'm totally off. Also, I think you'll be quicker to respond and might be interested in the temporary fix I have.



## How to test this.



I wrote this function to debug this issue:



```js

function analyzeTypes(filename, docs) {

  const relavantDocs = docs.reduce((acc, doc) => {

    if (!doc.fileInfo?.relativePath?.includes(filename)) {

      return acc;

    }



    return [

      ...acc,

      {

        id: doc.id,

        docType: doc.docType,

        type: doc.type,

        // Note: These line numbers don't seem to match *exactly* with the file.

        // Not sure why. They almost match though.

        startingLine: doc.startingLine,

        endingLine: doc.endingLine,

        overloads: doc.overloads?.map((doc) => doc.id),

      },

    ];

  }, []);

  console.log();

  console.log(`-- TYPE ANALYSIS ${filename} --`);

  console.log();

  console.log(relavantDocs);

  console.log();

}

```



It can be defined and called in `docs_app/tools/transforms/angular-api-package/processors/filterContainedDocs.js`. Here is where and how I call it:



```js

// ...

$process: function (docs) {

      var docTypes = this.docTypes; // line 11

      analyzeTypes('internal/observable/concat.ts', docs);

// ...

```



The key information it logs is the `docType` of the docs array elements. Context: `filterContainedDocs` filters away certain docTypes; One being `'function-overload'`



## Current output of my function:



```js

[

  {

    id: 'index/concat',

    docType: 'function',

    type: '',

    startingLine: 5,

    endingLine: 6,

    overloads: [ 'index/concat()', 'index/concat(...args: any[])' ]

  },

  {

    id: 'index/concat()',

    docType: 'function-overload',

    type: '',

    startingLine: 7,

    endingLine: 7,

    overloads: undefined

  },

  {

    id: 'index/concat(...args: any[])',

    docType: 'function-overload',

    type: 'Observable<unknown>',

    startingLine: 10,

    endingLine: 114,

    overloads: undefined

  },

  {

    id: 'index/concat~args',

    docType: 'parameter',

    type: 'any[]',

    startingLine: 113,

    endingLine: 112,

    overloads: undefined

  }

]

```

Notice the third element with id `index/concat(...args: any[])`. It got a docType of `'function-overload'` (clearly wrong. It's not an overload) resulting in it being filtered away.



## Quickfix



I'm still not exactly sure **why** this happens. I do know one fast way to fix it though: change the order of the overloads.



[`src/internal/observable/concat.ts`](https://github.com/ReactiveX/rxjs/blob/master/src/internal/observable/concat.ts) contains two overloads at the beginning of the file. If we move them to the bottom of the file we now get another output from my function -



## Quickfix output of my function:



```js

[

  {

    id: 'index/concat',

    docType: 'function',

    type: 'Observable<unknown>',

    startingLine: 5,

    endingLine: 109,

    overloads: [ 'index/concat()', 'index/concat()' ]

  },

  {

    id: 'index/concat~args',

    docType: 'parameter',

    type: 'any[]',

    startingLine: 108,

    endingLine: 107,

    overloads: undefined

  },

  {

    id: 'index/concat()',

    docType: 'function-overload',

    type: '',

    startingLine: 110,

    endingLine: 111,

    overloads: undefined

  },

  {

    id: 'index/concat()',

    docType: 'function-overload',

    type: '',

    startingLine: 112,

    endingLine: 112,

    overloads: undefined

  }

]

```



It's now correct! (this produces the beautiful docs in the screenshot from "**Expected behavior**" )



I would be more than happy to submit a PR with this fix. I think a few other operators has this problem. I could run through them all to make sure the ordering allows for expected docs.

[]