Edit the draft CG Report on Use Cases and Requirements

[tomoyukilabs]

According to CfC, we would like to start to draft the CG Report on Use Cases and Requirements.

• Preview: https://httpslocal.github.io/usecases/
• Draft (Bikeshed): https://github.com/httpslocal/usecases/blob/master/index.bs

The HTML version of this draft is generated by Bikeshed. Python 2.7 is required to run Bikeshed. To generate the HTML version by Bikeshed in your Python environment (e.g. virtualenv), you should run:

$ bikeshed spec index.bs index.html

Currently, the original version of bikeshed causes an error when trying to generate a CG report for HTTPSLocal. To avoid such an error, please clone and run the modified version of Bikeshed by @tomoyukilabs in httpslocal git branch: https://github.com/tomoyukilabs/bikeshed/tree/httpslocal.