hr_: Create a horizontal rule
In rich-iannone/hyper: Construct HTML and Javascript Using Piped Functions

Allows for the creation of a horizontal rule, which is used to signify a shift of topic or to separate content within an HTML page.

1	hr_(..., id = NULL, class = NULL, global = NULL)

`...`	a collection of HTML objects, textual elements (as bare text or Markdown-styled text), arbitrary attributes (given as named variables).
`id`	a global attribute for specifying a unique ID for an HTML element (the value must be unique within the HTML document, though, this is not currently enforced here). The primary use of the `id` attribute is to point to a style in a style sheet. The `id` is also used by JavaScript (via the HTML DOM) to manipulate the element with the specific `id`. When constructing an `id`, there are a few other things to note: (1) it must contain at least one character, (2) it must not contain any space characters, and (3) in HTML, all values are case-insensitive.
`class`	a global attribute for specifying one or more classnames for an element. The `class` attribute is primarily used in pointing to a class in a style sheet. However, this attribute can also be used by a JavaScript (via the HTML DOM) to make changes to HTML elements with a specified class. If providing several classes, one can either use `c("[classname1]", "[classname2]", ...)` or a single string with space-separated class names. When constructing class names, there are two things to keep in mind: (1) they begin with a letter (`A-Z` or `a-z`), and (2) subsequent characters can be letters (`A-Za-z`), digits (`0-9`), hyphens, and underscores.
`global`	provides an opportunity to supply global attributes other than the `id` and `class` attributes (which have their own arguments). This is most easily accomplished via the namesake `global()` function since it allows for inline help and validation for each of the global attributes. For example, setting the global attributes `title` and `lang` can be done by using this: `global = global(lang = "en", title = "my_title")`.