state snapshot images

CHANGELOG.md

src/mol-plugin-state/manager/snapshots.ts

src/mol-plugin-ui/skin/base/components/misc.scss

src/mol-plugin-ui/skin/base/variables.scss

src/mol-plugin-ui/state/snapshots.tsx

src/mol-plugin/behavior/static/state.ts

src/mol-plugin/state.ts

src/mol-util/assets.ts