Feature request: add a checkbox to search for whole words

[Omaeda]

Description:
Please add a checkbox option in the search functionality to allow users to search for whole words only. This feature would be beneficial for users who need precise search results without partial matches.

Steps to Reproduce:

1. Go to the search bar.
2. Enter a search term. (for title or comments)
3. Observe that the search results include partial matches.

Expected Behavior:
When the checkbox is selected, the search results should only include whole word matches.

Actual Behavior:
Currently, the search results include both whole word and partial matches.

Example: