Documentation: Noting on previous alternatives

[BradKML]

There are other repos that attemps something similar in https://github.com/hhchen1105/networkx_addon
Some other algorithm good to note:

• LHN https://github.com/hhchen1105/networkx_addon/blob/master/similarity/lhn.py
• RSS2 https://github.com/hhchen1105/networkx_addon/blob/master/similarity/rss2.py