Update configuration documentation: deprecations, default locations for Policy file and other config files

[cstepanian]

The docs on path flags needs to be updated to reflect that:

• The config TOML format is deprecated
• The data folder is deprecated
• There is now a --policy flag

The docs for hc check also need to reflect these changes.

User questions the docs should be able to answer:

• Where does Hipcheck look for the Hipcheck.kdl policy file by default? (the exact paths will vary depending on platform and environment)
• What is the purpose of the other config files? (Binary.toml, Langs.toml, Orgs.kdl, Typos.toml)