New doc section: codesnippets / Advanced Examples

Presents code examples that use the instaloader module for more advanced tasks
than what is possible with the Instaloader command line interface.

Presents #46, #56, #110, #113, #120, #121.

docs/codesnippets/113_only_one_per_user.py

@@ -0,0 +1,14 @@
+import instaloader
+
+L = instaloader.Instaloader()
+
+posts = L.get_hashtag_posts('milfgarden')
+
+users = set()
+
+for post in posts:
+    if not post.owner_profile in users:
+        L.download_post(post, '#milfgarden')
+        users.add(post.owner_profile)
+    else:
+        print("{} from {} skipped.".format(post, post.owner_profile))