update intellisense docs to include intellij

[geoctrl]

intellij is very similar to vscode, just requires some settings digging:

tried submitting a PR but this repo is locked down 😢

[geoctrl]

or you guys can add it in yourselves 🤷

// add IntelliJ tab:
<Tabs items={['VSCode', 'Neovim', 'IntelliJ']}>

// add tab
  <Tab>
    If you are using **IntelliJ** and the [**Tailwind CSS Plugin**](https://plugins.jetbrains.com/plugin/15321-tailwind-css), go to **settings** -> **Languages & Frameworks** -> **Style Sheets** -> **Tailwind CSS** and add the following to the configuration.

    ```json copy
      "experimental": {
        "configFile": null,
        "classRegex": [
          ["tv\\((([^()]*|\\([^()]*\\))*)\\)", "[\"'`]([^\"'`]*).*?[\"'`]"]
        ]
      }
    ```

  </Tab>

[mskelton]

@geoctrl Why did submitting a PR not work? Did you make a fork of the repo first?

[geoctrl]

i don't do this enough 🤦 i didn't realize you can create a PR from a fork

#27