Add url for search.quarkus.io to be used in the templates

[marko-bekhta]

required for quarkiverse/antora-ui-quarkiverse#70

The theme template uses an environment variable for the search service, which should be defined when the site is built.

[github-actions]

🚀 PR Preview 7a99bfa has been successfully built and deployed to https://quarkiverse-docs-pr-159-preview.surge.sh

[gastaldi]

Can we use Antora's features and make it an Asciidoc Attribute instead? https://docs.antora.org/antora/latest/playbook/asciidoc-attributes/

[marko-bekhta]

Can we use Antora's features and make it an Asciidoc Attribute instead? https://docs.antora.org/antora/latest/playbook/asciidoc-attributes/

hmmm, it has been a while 🙈😃 ....

looking at where this one is used:

https://github.com/quarkiverse/antora-ui-quarkiverse/blob/d654b8f57850c6a9fa7565c57b271ada7886f822/gulp.d/tasks/download-search-app.js#L9

I'm not sure that we could leverage the asciidoc attribute from that particular JS script ...

[gastaldi]

Ah I see, I thought it was being used in the generated pages

[gastaldi]

That would require an Asciidoc extension or something else to read the values, but I am not sure it's worth the trouble. Do you want to make this PR ready for review so we can merge it?

[github-actions]

🙈 The PR is closed and the preview is expired.

[marko-bekhta]

I've updated related PRs. I think that we should start with:

• Index quarkiverse guides quarkusio/search.quarkus.io#260
  once we have that one in, we can then update the theme:
• Update the theme to include search components antora-ui-quarkiverse#70
  and then merge this PR. ( without search.quarkus.io and theme updates it doesn't bring much to merge this one 😕)