KeywordBear.py: Fix docstring
KeywordBear.py: Fix docstring

Change docstring to triple quotes and fix indentation of parameter
description.

Closes https://github.com/coala/coala-bears/issues/1797

coala/coala-bears,coala/coala-bears,coala/coala-bears,damngamerz/coala-bears,srisankethu/coala-bears,coala/coala-bears,damngamerz/coala-bears,damngamerz/coala-bears,refeed/coala-bears,coala/coala-bears,damngamerz/coala-bears,srisankethu/coala-bears,yash-nisar/coala-bears,ankit01ojha/coala-bears,coala-analyzer/coala-bears,shreyans800755/coala-bears,refeed/coala-bears,ankit01ojha/coala-bears,Vamshi99/coala-bears,yash-nisar/coala-bears,Vamshi99/coala-bears,Vamshi99/coala-bears,shreyans800755/coala-bears,shreyans800755/coala-bears,coala-analyzer/coala-bears,srisankethu/coala-bears,Vamshi99/coala-bears,coala-analyzer/coala-bears,coala-analyzer/coala-bears,ankit01ojha/coala-bears,ankit01ojha/coala-bears,damngamerz/coala-bears,coala/coala-bears,ankit01ojha/coala-bears,coala-analyzer/coala-bears,yash-nisar/coala-bears,Vamshi99/coala-bears,Vamshi99/coala-bears,aptrishu/coala-bears,refeed/coala-bears,shreyans800755/coala-bears,shreyans800755/coala-bears,ankit01ojha/coala-bears,coala/coala-bears,shreyans800755/coala-bears,ankit01ojha/coala-bears,yash-nisar/coala-bears,srisankethu/coala-bears,damngamerz/coala-bears,refeed/coala-bears,aptrishu/coala-bears,shreyans800755/coala-bears,aptrishu/coala-bears,aptrishu/coala-bears,srisankethu/coala-bears,shreyans800755/coala-bears,shreyans800755/coala-bears,yash-nisar/coala-bears,coala/coala-bears,coala/coala-bears,aptrishu/coala-bears,refeed/coala-bears,coala-analyzer/coala-bears,coala-analyzer/coala-bears,damngamerz/coala-bears,yash-nisar/coala-bears,damngamerz/coala-bears,srisankethu/coala-bears,srisankethu/coala-bears,yash-nisar/coala-bears,Vamshi99/coala-bears,shreyans800755/coala-bears,damngamerz/coala-bears,refeed/coala-bears,yash-nisar/coala-bears,srisankethu/coala-bears,Vamshi99/coala-bears,ankit01ojha/coala-bears,aptrishu/coala-bears,Vamshi99/coala-bears,yash-nisar/coala-bears,yash-nisar/coala-bears,Vamshi99/coala-bears,ankit01ojha/coala-bears,srisankethu/coala-bears,refeed/coala-bears,aptrishu/coala-bears,srisankethu/coala-bears,coala/coala-bears,shreyans800755/coala-bears,srisankethu/coala-bears,aptrishu/coala-bears,damngamerz/coala-bears,ankit01ojha/coala-bears,refeed/coala-bears,coala-analyzer/coala-bears,ankit01ojha/coala-bears,refeed/coala-bears,yash-nisar/coala-bears,refeed/coala-bears,aptrishu/coala-bears,damngamerz/coala-bears,coala/coala-bears,aptrishu/coala-bears,refeed/coala-bears,aptrishu/coala-bears,Vamshi99/coala-bears,coala-analyzer/coala-bears,coala/coala-bears