Description

This PR:

• Closes Default pagefind ranking weights are not applied to meged indexes #2989
• Set up default values to the ranking property of merged indexes in pagefind to prevent search collision research between the current site and the sites hosting the merged indexes
• This PR do not changes starlight visual

Test

I've tested locally with 2 variants of the starlight's documentation:

1. The first variant is the one from the main branch, without any merged indexes nor any modifications
2. The second one is nearly the same as the one from the main branch, with little modifications:
   1. A markdown file changed, replacing climate impact by climate exchange
   2. And a merge index pointing to the first site on pagefind configuration

To test it I searched for climate exchange (the modified text) on the second site.

Before applying the fix, search shown the original site as first result, and after the fix, modified site was first in search result (due to corp. network policies I can't upload screenshot right now to prove it)

Details

I used this script to build and serve locally the 2 variants:

#! /bin/bash

echo "Installing serve globaly"
npm i -g serve

echo "Building the documentation for port 3001"
if [ -d "dist-3001" ]; then
    rm -rf "dist-3001"
fi
pnpm build
mv dist dist-3001

echo "Changing the content of the documentation"
sed -i 's/climate impact/climate exchange/' src/content/docs/environmental-impact.md
sed -i '52i\ \t\t\tpagefind: { indexWeight: 2.0, mergeIndex: [{ bundlePath: "http://localhost:3001/pagefind/", indexWeight: 0.5, }] },' astro.config.mjs


echo "Building the documentation for port 3002"
if [ -d "dist-3002" ]; then
    rm -rf "dist-3002"
fi
pnpm build
mv dist dist-3002

echo "Serving the 2 sites"
serve -l 3001 --cors ./dist-3001 &
serve -l 3002 --cors ./dist-3002