Multiple elements -> Existing README

[bennypowers]

It would be nice if wca had an option to concatenate its output to an existing README.md, while bumping up it's header levels.

Input:

/**
 * @element 'super-man'
 * @attr {String} [weakness="kryptonite"] - supe's ultimate weakness
 *
 * ### Usage
 * ```html
 * <super-man weakness="lois-lane"></super-man>
 * ```
 */
class SuperMan extends HTMLElement {}

/**
 * @element 'spider-man'
 * @attr {'classic'|'alien'} [suit="classic"] - type of spidey suit
 *
 * ### Usage
 * ```html
 * <spider-man suit="classic"></spider-man>
 * ```
 */
class SpiderMan extends HTMLElement {}

Existing README.md

# Super Elements
Super elements for super developers.
Here's a bunch of emoji
[![made with open-wc](https://img.shields.io/badge/made%20with-open--wc-%23217ff9)](https://open-wc.org)
[![Published on webcomponents.org](https://img.shields.io/badge/webcomponents.org-published-blue.svg)](collection/super-elements/smart-elements-community)

Output:

# Super Elements
Super elements for super developers.
Here's a bunch of emoji
[![made with open-wc](https://img.shields.io/badge/made%20with-open--wc-%23217ff9)](https://open-wc.org)
[![Published on webcomponents.org](https://img.shields.io/badge/webcomponents.org-published-blue.svg)](collection/super-elements/smart-elements-community)

## super-man

### Usage
```html
<super-man weakness="lois-lane"></super-man>
```

| Property   | Attribute  | Modifiers | Type     | Default      | Description              |
|------------|------------|-----------|----------|--------------|--------------------------|
| `weakness` | `weakness` |           | `String` | 'kryptonite' | supe's ultimate weakness |

## spider-man

### Usage
```html
<spider-man suit="classic"></spider-man>
```

| Property | Attribute | Modifiers | Type             | Default   | Description         |
|----------|-----------|-----------|------------------|-----------|---------------------|
| `suit`   | `suit`    |           | `classic|alien`  | 'classic' | type of spidey suit |

This could be accomplished by the user with a little bash scripting and some regex, but it would be nice to have some --merge flag that defaults to README.md

[runem]

Hi, thanks for your suggestion :-)

I actually already have an undocumented config to set default markdown header level. This option is called --markdown.headerLevel. I just published version 1.0.2 that opens up for using this option.

In addition, I added a --silent flag that can be used to prevent WCA from reporting progress to the console.

Now your use case is supported by running the following command using version 1.0.2:

web-component-analyzer src --silent --markdown.headerLevel 2 >> README.md

In order to do this more elegantly, I suggest that we add options to the markdown output, that can be used to set a specific header or footer in the resulting markdown output. These options could be named --markdown.headerFile and --markdown.footerFile.

web-component-analyzer src --markdown.headerFile HEADER.md --outFile README.md

Would that suggestion cover your use case?

[bennypowers]

That would be ideal, thanks 😁

[tpluscode]

I think this and #159 are indeed duplicates. @bennypowers please see my "magic comment" suggestion.