Fix/review ftl init and ftl new command behaviors

[wesbillman]

A couple things we noticed in the demo video and want to fix/review.

• ftl init should create a new directory for a project (vs. having to mkdir then cd then ftl init

ftl init <project name> [folder name]

Examples:
  ftl init my-app        # Creates a new folder named "my-app" and initializes it.
  ftl init my-app .      # Initializes the current directory as "my-app".
  ftl init my-app custom # Creates a folder named "custom" and initializes it as "my-app".

• ftl new go seemed to print out some debug messages. Check into why that is happening...
• Update current docs as needed to reflect these changes (both cli docs and docs docs)