* struct-conn extension toy example

* Minor changes (David's feedback)

* Showing struct_conn visuals

* Removed Interactions visual

* Caching struct_conns

* Removed testing buttons in index.html, updated CHANGELOG

* Addressed most of PR feedback

* Fixed structure node selection, docs

* Addressed feedback round 2

* feat: partial charges extension

* chore: pullrequest actions

* feat: example

* fix: review changes

* fix: updated example structure categories

* fix(changelog): shorter description

* fix: code review changes

* fix: cosmetic changes