Updating dashR component generation

[HammadTheOne]

This PR adds a minor change to the dashR component generation by adding an export tag so component functions are automatically added to the NAMESPACE with devtools::document().

[alexcjohnson]

This is probably due to a minor NPM version difference between your env and whoever last updated this file (likely me)... not a big deal, but let's try not to commit changes like this.

[HammadTheOne]

Do we want to keep the package name? For reference, my npm version is 7.15.1 (and node is 16.3.0).

[alexcjohnson]

I'm on 7.21.0, 16.8.0 - so yeah, I think this is a new addition to the package-lock format that we should keep.

[HammadTheOne]

After upgrading to npm 8.0.0 the name key is now set. Fixed in 01c5803.

[alexcjohnson]

Weird that we get all this extra whitespace... there was a little bit of it before - like https://github.com/plotly/dash/pull/1798/files#diff-636f7fc815f56fa24377d9d5d7df894abf0ba39621713316f3af387bb5d70c13L310 - but we should really get rid of this, as it DOES make it into the final built components. For example here's height in Img.py right now:

    - height (string | number; optional):
        Specifies the height of elements listed here. For all other
        elements, use the CSS height property.        Note: In some
        instances, such as <div>, this is a legacy attribute, in which
        case the CSS height property should be used instead.

[alexcjohnson]

Looks like here:

dash/components/dash-html-components/scripts/extract-attributes.js

Lines 71 to 75 in b32ac95

	const description = $children.eq(2).text()
	.replace(/\n/g, '')
	// Fix irregular whitespace characters
	.replace(' ', ' ')
	.trim();

IDK what replace(' ', ' ') is supposed to accomplish, but I suspect just turning it into .replace(/\s+/g, ' ') would do the trick

[HammadTheOne]

That fixed it! 01c5803

[alexcjohnson]

💃 Excellent!