chore(config): Document all configuration options

[rashil2000]

Description

Motivation and Context

Closes #2270

How Has This Been Tested?

Checklist:

• I have updated the documentation accordingly.
• I have updated the tests accordingly.

[rashil2000]

Let me know if I missed any setting

[niheaven]

force-update: Force apps updating to bucket's version
shim: Choose scoop shim builds
rootPath: Root path of scoop, default '$env:USERPROFILE\scoop'
globalPath: Global root path of scoop, default '$env:ProgramData\scoop'
cachePath: Cache path of scoop, default '$rootPath\cache'

[rashil2000]

Can we actually use variables in the config values? Will scoop do a string substitution on them?

[niheaven]

Environment Variables could be used, but other local variables should not.

[rashil2000]

Then $rootPath\cache shouldn't be used, right?

[niheaven]

Yes, it is the default value, but user cannot set as is.

[rashil2000]

Right.
So if we show

# cachePath: $rootPath\cache

in the help doc, users will think it's okay to use variables.

So we should either leave it empty (and write default value in description), or write an example valid path here.

[niheaven]

Use 'cache' folder under Scoop root directory?

[rashil2000]

@niheaven done

[rashil2000]

Should we also document environment variables used by scoop? Like SCOOP and SCOOP_CHECKVER_TOKEN. Are there any more?

[niheaven]

In wiki or homepage, IMO.

SCOOP, SCOOP_GLOBAL, SCOOP_CACHE, read before rootPath, globalPath, cahePath config.

[rashil2000]

Updated the Readme 👍