Remove unnecessary/incorrect information about installation (#2135)

Addresses #2134


[Here](https://tailwindcss-com-git-fork-xkjjx-railsv4-docu-ea85af-tailwindlabs.vercel.app/docs/installation/framework-guides/ruby-on-rails)
is the link to the preview, and
[here](https://tailwindcss.com/docs/installation/framework-guides/ruby-on-rails)
is the current version.

Author: xkjjx

src/app/(docs)/docs/installation/framework-guides/ruby-on-rails.tsx

@@ -63,22 +63,6 @@ export let steps: Step[] = [
       `,
     },
   },
-  {
-    title: "Import Tailwind CSS",
-    body: (
-      <p>
-        Add an <code>@import</code> that imports Tailwind CSS to your <code>application.tailwind.css</code> file located
-        in the <code>./app/assets/stylesheets</code> directory.
-      </p>
-    ),
-    code: {
-      name: "application.tailwind.css",
-      lang: "css",
-      code: css`
-        @import "tailwindcss";
-      `,
-    },
-  },
   {
     title: "Start your build process",
     body: (