[madokami] add 'manga' extractor (#7828)

docs/configuration.rst

@@ -468,6 +468,7 @@ Description
     * ``inkbunny``
     * ``iwara``
     * ``kemono``
+    * ``madokami`` (R)
     * ``mangadex``
     * ``mangoxo``
     * ``newgrounds``

docs/gallery-dl.conf

@@ -447,6 +447,11 @@
         {
             "gif": false
         },
+        "madokami":
+        {
+            "username": "",
+            "password": ""
+        },
         "mangadex":
         {
             "client-id"    : "",

docs/supportedsites.md

@@ -583,6 +583,12 @@ Consider all listed sites to potentially be NSFW.
     <td>Albums, Search Results</td>
     <td></td>
 </tr>
+<tr>
+    <td>Madokami</td>
+    <td>https://manga.madokami.al/</td>
+    <td>Manga</td>
+    <td>Required</td>
+</tr>
 <tr>
     <td>Manga Fox</td>
     <td>https://fanfox.net/</td>