update description and pricing of letters card on landing page

[emmagifford]

Description

I have updated the pricing and description for the letters card on the landing page. This can be found in the folder website > data > home > pricing.yml. It now says 'standard postage' and '64 pence' instead of the old blended postage rate.

I've also changed the styling of 'p' to 'pence' in line with the NHS and GDS content guides.

Context

This is needed to bring the landing page pricing content in line with the latest letter price changes from last week. It was a complete oversight of mine to forget to update the landing page content on that PR.

Just to note, I did try to include more content in the description, such as 'one double-sided sheet' but this made the text span too many lines and it overlapped with the '64 pence'.

Type of changes

• Refactoring (non-breaking change)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would change existing functionality)
• Bug fix (non-breaking change which fixes an issue)

Checklist

• I am familiar with the contributing guidelines
• I have followed the code style of the project
• I have added tests to cover my changes
• I have updated the documentation accordingly
• This PR is a result of pair or mob programming

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Sensitive Information Declaration

To ensure the utmost confidentiality and protect your and others privacy, we kindly ask you to NOT including PII (Personal Identifiable Information) / PID (Personal Identifiable Data) or any other sensitive data in this PR (Pull Request) and the codebase changes. We will remove any PR that do contain any sensitive information. We really appreciate your cooperation in this matter.

• I confirm that neither PII/PID nor sensitive data are included in this PR and the codebase changes.

[jamestynan-content]

All looks good