Auto merge of #7694 - danielparks:issue-7691-manifest-badges-section, r=ehuss

Auto merge of #7694 - danielparks:issue-7691-manifest-badges-section, r=ehuss

Clarify manifest format docs for [badges] section

Previously the `[badges]` section documentation was mixed in with the `[package]` section. This extracts it out under its own heading.

This also pulls the `license` and `license-file` field documentation out of the package metadata code block. It sets the example license to “MIT OR Apache-2.0” since that is the typical licensing scheme for many crates.

This includes minor rewrites for clarity and to match the register of the rest of the document.

This resolves issue #7691.