Add site title.

Signed-off-by: Ville Korhonen <ville.korhonen@ylioppilastutkinto.fi>
Add OpenSearch description.
Add initial robots.txt.
Add initial .editorconfig.
Add initial tagline.
Add configuration for *.scss, *.sass.
Add initial SASS styles.
Add initial default layout.
Use default layout.
Remove OpenSearch description temporarily.