Add Google Custom Search for spinkube.dev

[ThorstenHans]

An instance of Google Custom Search (GCS) has been added and configured to index contents from .spinkube.dev/

The GCS has been created using the spin.maintainers@gmail.com account.

fixes #1

[vdice]

GCS ID update looks good to me -- I'm assuming this isn't testable locally? (Looking at this: https://github.com/spinkube/documentation/blob/main/hugo.toml#L126 which seems like it'd use a diff searching engine anyways?)

nit: I kind of like the toml indentations for readability but not a strong opinion. Defer to any others who might have one.

[ThorstenHans]

Oh, so that was "Better TOML".

I'm happy to revert the indention. However, I don't have access to a computer at the moment. Can update this PR tomorrow morning CET

[ThorstenHans]

GCS ID update looks good to me -- I'm assuming this isn't testable locally? (Looking at this: https://github.com/spinkube/documentation/blob/main/hugo.toml#L126 which seems like it'd use a diff searching engine anyways?)

I've changed the visualization of the search results to be in-place instead of an overlay (modal dialog) which was a kind of distracting.

Indexing of the pages can take a while (according to GCS docs)

[tpmccallum]

Thanks @ThorstenHans @vdice

[vdice]

Is custom search working for y'all as you'd expect?

When I type in terms like 'shim', 'kubernetes', 'plugin', etc, I get no results. Typing 'spin' does give one result: a link to the spinkube.dev website. Wondering if I have a cached version or something, so thought I'd inquire.