Fix broken links

Fixes

Build errors encountered. Book 'user' in language 'English' was not published. There was a build error: 'MkDocs was unable to build the book. MkDocs command output: INFO - Cleaning site directory
INFO - Building documentation to directory: /var/www/civicrm-docs/var/cache/prod/publishing/publish_user_en_1653493417
INFO - The following pages exist in the docs directory, but are not included in the "nav" configuration:
- searching/relative-date-formats.md
[33mWARNING - [0mDocumentation file 'searching/searchkit/what-is-searchkit.md' contains a link to 'searching/searchkit/the-user-interface/creating-new-forms/creating-new-forms.md' which is not found in the documentation files.
[33mWARNING - [0mDocumentation file 'the-user-interface/searching-url-support.md' contains a link to 'the-user-interface/search-kit.md' which is not found in the documentation files.
'