OpenSearch protocol XML file

[mortenpi]

A long time ago it was suggested on Discourse that the search should have an OpenSearch file which the browsers should be able to pick up automatically. Something like:

<OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/">
<ShortName>Julia reference manual</ShortName>
<Description>Search in the official Julia documentation</Description>
<Image>https://docs.julialang.org/favicon.ico</Image>
<InputEncoding>UTF-8</InputEncoding>
<Url type="text/html" template="https://docs.julialang.org/en/v1/search/?q={searchTerms}"/>
</OpenSearchDescription>

I am not super-familiar with this myself, but it looks like something that might be worth exploring. I think it should be easy for deploydocs to generate this automatically.