deprecate transform attributes

Author: archmoj

src/components/calendars/index.js

@@ -234,6 +234,7 @@ module.exports = {
             }
         },
         transforms: {
+            description: 'This attribute is deprecated and it may be removed from the API in next major version.',
             filter: {
                 valuecalendar: makeAttrs([
                     'Sets the calendar system to use for `value`, if it is a date.'

src/plots/attributes.js

@@ -167,6 +167,7 @@ module.exports = {
         _isLinkedToArray: 'transform',
         editType: 'calc',
         description: [
+            'This attribute is deprecated and it may be removed from the API in next major version.',
             'An array of operations that manipulate the trace data,',
             'for example filtering or sorting the data arrays.'
         ].join(' ')