RFC documents for community feedback on proposed changes and improvements

See https://github.com/PowerShell/powershell-rfc/blob/master/RFC0000-RFC-Process.md for process information

The PowerShell Team meets once or twice a month (depending on amount of feedback) to review the feedback and respond. Since we are still testing the process, we've decided that over the next month, we'll author a few more RFCs based on existing known requests from the community. We'll continue to use this trial period to learn how to improve the process before we put this process into production. Thanks for everyone's contributions so far!

Note that this used to be called PowerShell-Language-RFC, but are opening this up for all types of change discussion including modules, cmdlets, etc...