unique storage keyspace/table/directory in the properties files

A common problem users run into when using the properties files found in the `conf` directory in the distribution is that they use a default name keyspace/table/directory. This runs into problems when the user decides to add or to switch between different indexing providers because the previous configuration is stored in the graph itself. Unless the user drops the previous graph, they will run into an exception.

- The properties files should have a unique keyspace/table/directory name associated with it to reduce the possibility of it happening.
- Add some documentation for troubleshooting this common issue

Start by reviewing the properties files in the distribution's conf directory and compare the default keyspace, table, and directory names. Document the configuration and troubleshooting steps for switching indexing providers without conflicts. Done means the defaults are unique and the common previous-graph exception is explained.

Written by the indexing model from the issue text.