Add post form

### Description of issue :

If I click the photo URL contain its go to the another page and image preview colour pattern is not good

### Expected result :

correct URL pattern form validation colour pattern good form validation

### Actual result :

wrong URL contain image preview colour pattern is not good

### Steps to reproduce :
1. give a correct URL contain make a good form validation form
2. give a correct colour pattern and meaning full buttons
3.

```
Path: /assest/pages/new_post
Browser: Chrome 112.0.0.0 on Windows 10
Viewport: 1504 x 860 @1.5x
Language: en-GB
Cookies: Enabled
```

[Open in BrowserStack](https://www.browserstack.com/user/try-live?url=https%3A%2F%2Fdeploy-preview-1--freshbye.netlify.app%2Fassest%2Fpages%2Fnew_post&os=Windows&os_version=10&browser=Chrome&browser_version=112.0&resolution=1504x860&speed=1&start=true&ref=netlify-source)

Submitted from [Netlify Deploy Preview #1](https://deploy-preview-1--freshbye.netlify.app/assest/pages/new_post)

Start at /assest/pages/new_post and reproduce the issue in Chrome using the linked deploy preview. Review the photo URL handling, image preview colors, form validation, and button wording. Done means invalid URLs are handled correctly and the preview, validation, colors, and buttons match the expected result.

Written by the indexing model from the issue text.