D15105: add JSON to general.entities

[Luigi Toscano]

ltoscano accepted this revision as: ltoscano.

REPOSITORY
  R238 KDocTools

REVISION DETAIL
  https://phabricator.kde.org/D15105

To: lueck, #documentation, yurchor, ltoscano
Cc: kde-frameworks-devel, kde-doc-english, michaelh, ngraham, bruns, skadinna