chore: reorganize playground

development/playground/context-help/index.html

development/playground/context-help/main.js

development/playground/context-help/main.pcss

development/playground/custom-element/index.html

development/playground/custom-element/main.mjs

development/playground/custom-element/main.pcss

development/playground/data-monster-bind/index.html

development/playground/data-monster-bind/main.mjs

development/playground/datatable/data.json

development/playground/datatable/index.html

development/playground/datatable/main.js

development/playground/dialog/index.html

development/playground/dialog/main.js

development/playground/dialog/main.pcss

development/playground/dom-arguments/index.html

development/playground/dom-arguments/main.mjs

development/playground/dom-arguments/translation.json

development/playground/dom-insert/index.html

development/playground/dom-insert/main.mjs

development/playground/dom/index.html