Docs: Vale flags every Plone and Cookieplone as an error #232

Running Vale on the docs (make docs-vale, or bin/vale on a single page) reports errors on every page that aren't real problems:

• Use '-{0,1}plone-{0,1}' instead of 'Plone' (Vale.Terms), wherever the docs write "Plone".
  • The first entry of styles/config/vocabularies/Plone/accept.txt is the pattern -{0,1}plone-{0,1}, in lowercase.
  • Vale treats accept entries as the preferred spelling, so a capitalized "Plone" is flagged against it, even though Plone is also in the list.
• Did you really mean 'Cookieplone'? (Vale.Spelling): "Cookieplone" isn't in the vocabulary.

Because of this, the docs' real errors drown in the noise. For example, docs/development/block-anatomy.md shows 17 errors, all of them the Plone term.

To do:

• Fix or replace the -{0,1}plone-{0,1} entry, for example by making it case-insensitive, (?i)-?plone-?, or by moving the hyphenated forms to their own entries.
• Add Cookieplone.
• Check that make docs-vale then only reports real issues.