Bump WP compatibility

See merge request !8

Don't be so specific, letting the API supply the point version.

See merge request !7

Update README

See merge request !6

Fix Spanish translation following coding-standards updates

Closes #5

See merge request !5

Numbered placeholders were added, unintentionally invalidating existing
translations.

Fixes #5.

Add bulk actions

Closes #1 and #4

See merge request !4

Fixes #4

Unit tests and coding standards

Closes #2 and #3

See merge request !3

Fixes #3, which was a misdiagnosis.

Add screenshots previously missing from git

See merge request !2

Add automated WP.org deploys

See merge request !1