add: readme for networks and removed potter-network

Author: BeaMarton13

doc/source/community_detection_guide/networks/README.md

@@ -0,0 +1,36 @@
+### README for `game_of_thrones/GOT.graphml`
+
+The **`game_of_thrones/GOT.graphml`** file contains a character interaction network for Season 1 of the HBO series "Game of Thrones".
+
+---
+
+### License
+
+This data is licensed under a **Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License**.
+
+---
+
+### Source
+
+This file was built based on the following CSV file:
+https://raw.githubusercontent.com/mathbeveridge/gameofthrones/master/data/got-s1-edges.csv
+
+
+
+### README for `lesmis/lesmis.gml`
+
+The **`lesmis/lesmis.gml`** file contains a co-appearance network of characters from Victor Hugo's novel, "Les Misérables".
+
+---
+
+### License
+
+When using this data, please cite the following work:
+> D. E. Knuth, The Stanford GraphBase: A Platform for Combinatorial Computing, Addison-Wesley, Reading, MA (1993).
+
+---
+
+### Source
+
+This file was obtained from Mark Newman's repository of network datasets at the University of Michigan, located at the following URL:
+https://websites.umich.edu/~mejn/netdata/