schemaorg.css

diff docs/schemaorg.css static/search_files/schemaorg.css :(

• make sure docs/schemaorg.css has everything needed from static/search_files/schemaorg.css
• update Python + HTML + templates/ references to use the former
• remove the CSS files that we no longer need, and static/search_files folder too.

We should converge towards the one in docs/ after checking nothing got lost.

Also prettify.css is mis-cited in some pages currently; the file is in docs/ not search_files/