Add method chaining syntax for attributes

[Lemon] / README.markdown

# 🍋🏷 Lemon

## Usage

```js
import Lemon from "./mod.js";

const { p, a, em } = Lemon;

document.body.append(
  p`This is a ${em`very cool`} paragraph made with ${(
    a
      .class("gitlab-link")
      .style("color: orangered")
      .href("https://gitlab.com/kibigo/Lemon")
  )`Lemon`}.`,
);
```