runSearch.php should optionally output the following info:
- query: the query
- totalHits: total number of hits found
- hits: array of results with pageId, title, and snippets (the number of displayed result should be 20 by default)
Default operation should not change.
Output should be in a reasonable JSON format, on a single line. Investigate whether we need an additional library to write valid JSON, given the complexity of the output.