Enhanced category filtering

[idanidan29]

What kind of change does this PR introduce?

Feature – This PR allows blog posts to belong to multiple categories instead of just one. and improve the filtering to filter more than one category

Issue Number:

• Closes ✨ Enhancement: Allow blogs to have multiple categories and enable filtering by multiple categories #1425

Screenshots/videos:

*I added the category to the blog only for the example picture and did not actually change the blog in the pic.

Summary

• The blog data structure is updated to support an array of categories.
• The UI now renders each category as a separate clickable badge.
• Users can filter by multiple categories at once.
• Filtering logic has been improved to sort posts by the number of matching categories when multiple filters are selected.

Blog posts now support multiple categories by framing them like this in the blog file:

type:
  - Case Study
  - Engineering

This enhancement improves content organization, filtering functionality, and provides greater flexibility for authors.

Does this PR introduce a breaking change?
no