fix: duplicate search content when /README or / exists in the sidebar

[sy-records]

Summary

fix: duplicate search content when /README or / exists in the sidebar.

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[jhildenbiddle]

I tested this PR locally and still encounter the issue. To reproduce the error:

1. Add the following line to _sidebar.md:

   - [README](README)
   

2. Launch test server with the following CLI command:

 node ./test/config/server.js --start

1. Search for "generator"

Results

We should also add tests for this scenario (no duplicates).

[sy-records]

I tested this PR locally and still encounter the issue. To reproduce the error:

1. Add the following line to _sidebar.md:

   - [README](README)
   

2. Launch test server with the following CLI command:

 node ./test/config/server.js --start

1. Search for "generator"

Results

You need to run npm run build:js first, then delete the local storage cache.

[jhildenbiddle]

@sy-records --

Fixed the test. Required updating the Playwright config to clear local storage before each test. I assumed that would have been done before, but apparently not. See the following branch: https://github.com/docsifyjs/docsify/tree/pullrequests/sy-records/fix-search

[jhildenbiddle]

LGTM!