fix: addDocusaurusMeta

[YOU54F]

Add metadata as per https://docusaurus.io/docs/api/themes/configuration#metadata to enable doc search again

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Issue

Doc search on docs.pact.io is not working

Cause

Looking the at the search request that is made from the docs pages., it doesn't return any results.

It appears to be down to the requests.params.facetFilters namely the docusaurus_tag's

They are set to ["language:en",["docusaurus_tag:default","docusaurus_tag:docs-default-current"]]

if I rerun the request dropping the array of docusauraus_tag's appears to fix the request.

I tried isolating either of the docusauraus_tag's and removing them from the array of facetFilters to no avail.

Remediation

https://v1.docusaurus.io/docs/en/search.html#extra-search-options
https://www.algolia.com/doc/api-reference/api-parameters/filters/#facet-filters

I think this issues are relevant :- TL;DR. looks out our config isn't quite right and we don't have pages marked with those tags.

facebook/docusaurus#5084 (comment)
facebook/docusaurus#3805

Looks like we made need to add some meta tags to the docs site - as they are not currently embedded in the site

<meta name="docsearch:docusaurus_tag" content="docs-default-current">

Hope this might work - we can add via the docusaurus config, metadata - see here

[bethesque]

You little ripper (there's some Aussie slang for you).