Problem: some standard copy paste formats do not work

Solution: add solution for copying text from Roam. This formats looks
like:
    - parent
        - child 1
        - child 2

The first line starts with a dash and space. The other lines also start
with spaces (multiple of 4 or 0), dash, space. Every 4 spaces is 1
indent in our format.

list-editor/index.js

@@ -523,7 +523,26 @@ function editor(root, inputData, options) {
             trigger('change')
             return false
         } catch (e) {
-            let items = pastedData.toString().split(/\n+/);
+            let inputString = pastedData.toString()
+            if (inputString.match(/^- /)) {
+                let item = $(this).parents('.list-item')
+                let id = item.attr('data-id')
+                let lines = inputString.split(/( *)- /)
+                lines.shift()
+                const firstItem = store.value(id)
+                const firstIndent = firstItem.indented
+
+                let items = _.map(_.chunk(lines, 2), line => {
+                    const indent = Math.trunc(line[0].length / 4);
+                    const item = newListItem(firstItem.indented+indent)
+                    item.text = _.trimEnd(line[1]).replace(/\n/g, "  \n")
+                    return item
+                })
+                store.insertAfter(id, ...items)
+                trigger('change')
+                return false
+            } else {
+                let items = inputString.split(/\n+/);
                 let item = $(this).parents('.list-item')
                 let id = item.attr('data-id')
                 if (items.length === 1) {
@@ -540,6 +559,7 @@ function editor(root, inputData, options) {
                 }
                 return false
             }
+        }
     });
 
     function moveCursor(event, dir) {