Indicates that PostCSS should add annotation comments to the CSS. By default, PostCSS will always add a comment with a path to the source map. PostCSS will not add annotations to CSS files that do not contain any comments.
By default, PostCSS presumes that you want to save the source map as
opts.to + '.map' and will use this path in the annotation comment.
A different path can be set by providing a string value for annotation.
If you have set inline: true, annotation cannot be disabled.
Override from in map’s sources.
Indicates that the source map should be embedded in the output CSS
as a Base64-encoded comment. By default, it is true.
But if all previous maps are external, not inline, PostCSS will not embed
the map even if you do not set this option.
If you have an inline source map, the result.map property will be empty,
as the source map will be contained within the text of result.css.
Source map content from a previous processing step (e.g., Sass).
PostCSS will try to read the previous source map automatically (based on comments within the source CSS), but you can use this option to identify it manually.
If desired, you can omit the previous map with prev: false.
Indicates that PostCSS should set the origin content (e.g., Sass source) of the source map. By default, it is true. But if all previous maps do not contain sources content, PostCSS will also leave it out even if you do not set this option.
Use absolute path in generated source map.