Add ClearProse

[adamtheturtle]

Adds ClearProse, a small style package for reStructuredText.

It contains one rule, ClearProse.NoEmDash, which reports the Unicode em dash (U+2014) as an error in prose.

Relationship to existing packages

RedHat.EmDash already prohibits em dashes, so it is worth saying where this differs rather than leaving you to find out.

That rule sets scope: raw, so it matches the source text rather than the parsed document. In reStructuredText that means it reports em dashes inside code blocks and inline literals. Run against this package's fixtures, it reports 14 alerts in the two files that hold em dashes in code, where ClearProse.NoEmDash reports none. It is also a warning rather than an error, and it arrives as one rule among 37 in a style guide written for Red Hat documentation.

Google.EmDash and Microsoft.Dashes match \s[—–]\s and ask for the spaces to be closed up. They permit the em dash itself, so neither conflicts with this rule.

Checks

Run locally before opening this:

• pytest tests passes (valid JSON, alphabetical order, required keys, working homepage and url).
• The verification step passes: ClearProse.zip downloads from releases/latest, contains a single ClearProse/ directory, and loads into Vale with exit 0.

The archive is built reproducibly by a release workflow and is byte-identical across the release assets and a local build. The package repository has its own CI that runs fixture tests against a pinned Vale, and is MIT licensed.