Drop support of setting title to string (instead of title.text) in v3?

[archmoj]

No description provided.

[gvwilson]

@archmoj what's the background for this one?

[archmoj]

When title is added in plotly.js it only accepted a string e.g. title: 'The titlte'.
Later on more options were needed to control the title e.g. font.
Therefore title could be an object with multiple keys e.g.

title: {
  text: 'The title',
  font: ...
  ...
}

The proposal here is to drop the deprecated form, when title is set to a string e.g. title: 'The titlte'.

[alexcjohnson]

Several years ago we expanded all the title attributes from strings to dicts, with the original string moved to the text field inside the dict. But we kept it backward compatible, so a figure supplied with a string gets converted to the dict form automatically. This leads to confusion, both because people will see examples done both ways and because anyone using the old one will then inspect their graphs and see something else in them, so it’s probably time to remove this compatibility layer.