Implementing search on Apertis website

The statically generated site currently does not currently offer search functionality. Whilst we could rely to a degree on search engines to index the Apertis website (for example by using the provided integration of Google Custom Search Engine) but it is expected that the website will be used as the basis for more taylored sites by users of Apertis that may be implemented out of the reach of the search engines indexing and thus localised search is required.

Remove the Google search integration in the theme and instead integrate local search based on the approach documented here:

https://gist.github.com/eddiewebb/735feb48f50f0ddd65ae5606a1cb41ae#layouts_defaultsearchhtml

Signed-off-by: Martyn Welch martyn.welch@collabora.com