cleanup!(config.xml): simplify defaults

[erisu]

Platforms affected

all

Motivation and Context

Not all apps require the pre-define settings that we prodived.

The core template should be as minimalist as possible.

Description

• Removed all predefined settings except for the basic allow-intent of http and https, so pages can continue to open the system browser.
• Provide a simple instruction for access, allow-navigation and allow-intent.
• Include 1 example for access and allow-navigation. allow-intent was excluded because it contains an actual usage.
• Added direct link to the access, allow-navigation and allow-intent documentation anchor point.

Other Changes:

• Shorten the template description
• Updated author url
• Formatted XML

Checklist

• I've updated the documentation if necessary
  • The website documentation should list our the old defaults, not just in example configs, so users can read how to enable certain features. E.g. tel, geo, sms, etc...

[dpogue]

IMO this significantly improves the default security settings for new Cordova apps, and will make people think about what origins they actually need to allow