fix: repair template rendering on screenshots page

[taniishq13]

The screenshots.html page was displaying raw placeholder text such as
{page.title} and {page.content} instead of the actual page values.

✔ What I changed

I updated the placeholder format to use the proper double-brace style:

• {page.title} → {{ page.title }}
• {page.content} → {{ page.content }}
• {page.keywords} → {{ page.keywords }}
• {page.summary} → {{ page.summary }}

I also updated the page heading:

• <h1>Page</h1> → <h1>{{ page.title }}</h1>

✔ Why this helps

The file previously used an incorrect placeholder format, causing the website to show them literally.
The corrected format matches the placeholder style used in the rest of the project.

This PR fixes the placeholder formatting.
If additional configuration is required to process the page during site generation, it can be handled separately.

No functional code changes — template text only.