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/110_pil_captions.py

@@ -0,0 +1,20 @@
+from io import BytesIO
+
+from requests import get
+from PIL import Image, ImageDraw
+from instaloader import *
+
+L = Instaloader()
+
+# Load Post instance
+post = load_structure_from_file(L.context, '2017-10-01_18-53-03_UTC.json.xz')
+# or post = Post.from_shortcode(L.context, SHORTCODE)
+
+# Render caption
+image = Image.open(BytesIO(get(post.url).content))
+draw = ImageDraw.Draw(image)
+color = 'rgb(0, 0, 0)'  # black color
+draw.text((300,100), post.caption.encode('latin1', errors='ignore'), fill=color)
+
+# Save image
+image.save('test.jpg')