Merge branch 'feature/goto-page' into 'develop'

app/apps/api/serializers.py

app/apps/api/views.py

app/apps/core/models.py

app/escriptorium/templates/core/document_images.html

app/escriptorium/templates/core/document_list.html

app/escriptorium/templates/core/document_nav.html

front/css/escriptorium.css

front/src/editor/api.js

front/src/editor/store/document.js

front/src/editor/store/parts.js

front/src/image_cards.js

front/vue/components/Editor.vue

front/vue/components/ExtraInfo.vue