Update README to link to new wiki tutorials #74
Update README to link to new wiki tutorials #74

  * Replaces existing link to wiki with link to wiki section on
    tutorials.
  * Previously modified wiki to add sections documenting (1) importing
    JSON and exporting SQLite to JSON and (2) opening and saving a
    SQLite file.

Signed-off-by: John M. Horan <62b1a4b1cb52bcf40f8267031eadbe72224a36da@gmail.com>

nexB/aboutcode-manager,nexB/aboutcode-manager,nexB/aboutcode-manager