[kemono][coomer][schalenetwork] rename modules & extractors

category changes:

- kemonoparty -> kemono
- coomerparty -> coomer
- koharu      -> schalenetwork

also wanted to rename '2chan' -> 'sturdychan',
but the site's main page is still titled '2chen'

docs/supportedsites.md

@@ -836,7 +836,7 @@ Consider all listed sites to potentially be NSFW.
     <td></td>
 </tr>
 <tr>
-    <td>SchaleNetwork</td>
+    <td>Schale Network</td>
     <td>https://niyaniya.moe/</td>
     <td>Favorites, Galleries, Search Results</td>
     <td></td>