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/120_ghost_followers.py

@@ -0,0 +1,27 @@
+import instaloader
+
+L = instaloader.Instaloader()
+
+USER = 'your_account'
+PROFILE = USER
+
+# Your preferred way of logging in:
+L.load_session_from_file(USER)
+
+profile = instaloader.Profile.from_username(L.context, PROFILE)
+
+likes = set()
+print('Fetching likes of all posts of profile {}.'.format(profile.username))
+for post in profile.get_posts():
+    print(post)
+    likes = likes | set(post.get_likes())
+
+print('Fetching followers of profile {}.'.format(profile.username))
+followers = set(profile.get_followers())
+
+ghosts = followers - likes
+
+print('Storing ghosts into file.')
+with open('/YOUR PATH/inactive-users.txt', 'w') as f:
+    for ghost in ghosts:
+        print(ghost.username, file=f)