Add dropzone for attachment, paste attachment from clipboard

client/src/hooks/index.js

@@ -1,6 +1,7 @@
 import useField from './use-field';
 import useForm from './use-form';
 import useSteps from './use-steps';
+import useModal from './use-modal';
 import useClosableForm from './use-closable-form';
 
-export { useField, useForm, useSteps, useClosableForm };
+export { useField, useForm, useSteps, useModal, useClosableForm };