Feature: Give homepage hero background full width and height (#3985)

## Because
Upon initial loading of the homepage, the hero background moves around a
bit.
After solving this, the page will load smoothly due to browser knowing
the pre-made space the banner requires.

## This PR
- Adds ``class: 'w-full h-full' `` to the homepage
[banner](https://github.com/TheOdinProject/theodinproject/blob/main/app/views/static_pages/home.html.erb#L15)
element.

## Issue
Closes #3949


## Pull Request Requirements
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- [x] I have thoroughly read and understand [The Odin Project
Contributing
Guide](https://github.com/TheOdinProject/theodinproject/blob/main/CONTRIBUTING.md)
- [x] The title of this PR follows the `keyword: brief description of
change` format, using one of the following keywords:
  - `Feature` - adds new or amends existing user-facing behavior
- `Chore` - changes that have no user-facing value, refactors,
dependency bumps, etc
  - `Fix` - bug fixes
-   [x] The `Because` section summarizes the reason for this PR
- [x] The `This PR` section has a bullet point list describing the
changes in this PR
- [x] I have verified all tests and linters pass after making these
changes.
- [x] If this PR addresses an open issue, it is linked in the `Issue`
section
-   [x] If applicable, this PR includes new or updated automated tests

app/views/static_pages/home.html.erb

@@ -12,7 +12,7 @@
 
       <%= link_to 'View Full Curriculum', paths_url, class: 'button button--secondary text-base' %>
     </header>
-    <%= image_tag 'home-isometric.svg', alt: 'home-page-banner' %>
+    <%= image_tag 'home-isometric.svg', alt: 'home-page-banner', class: 'w-full h-full' %>
   </div>
 
   <%= render 'static_pages/home/how_it_works' %>