Please update the examples on the root ReadMe with latest implementations and examples

[SimonDarksideJ]

With all the recent changes, the main ReadMe has not been kept up to date, as such, none of the examples provided are functional and require additional parameters.

[StephenHodgson]

Nothing has really changed much since your large refactor in #65/#66.
If you'd like to open a PR to update the docs with the refactor changes you made there, you are more than welcome.

I've only updated logging string outputs and fixes a few concurrency bugs.
I did update Rest.DownloadAudioClipAsync but only added optional stream and compression parameters.

[SimonDarksideJ]

Essentially, although a single "RestParameters" example has been added, the other examples do not make it clear it is optional or required, additionally, some requests like AssetBundles are malformed.

But I will do a PR to correct this.