* Add optional serde feature
* Document features in README
* Add changelog entry
* Implement some missing derivable traits
* Add changelog entry for std derives
* Remove extraneous space on serde doc comments
* Add period to end of serde line in readme
* Remove serde impls from WindowAttributes
* Add serde impls for TouchPhase
* Add serde test file
* Add feature lines to testing CIs
* Remove WindowAttributes from changelog
