Build a search form

[edwardcrompton]

• [ ] The search form should be at /search
• [ ] There should be a text box in order to type a search term
• [ ] A search button will submit the form.
• [ ] When the form is submitted a list of results is displayed.
• [ ] The form should be Welsh first. We can introduce another language later

[edwardcrompton]

This seems to be made obsolete by completion of #10