feat(export): add export loading state and copy as markdown (#1867)

* feat: add loading state to export

* feat: copy as markdown

* preserve taskList comment

pnpm-lock.yaml

@@ -193,6 +193,9 @@ importers:
       '@types/bytes':
         specifier: ^3.1.5
         version: 3.1.5
+      '@types/turndown':
+        specifier: ^5.0.6
+        version: 5.0.6
       '@types/uuid':
         specifier: ^10.0.0
         version: 10.0.0
@@ -4812,6 +4815,9 @@ packages:
   '@types/trusted-types@2.0.7':
     resolution: {integrity: sha512-ScaPdn1dQczgbl0QFTeTOmVHFULt394XJgOQNoyVhZ6r2vLnMLJfBPd53SB52T/3G36VI1/g2MZaX0cwDuXsfw==}
 
+  '@types/turndown@5.0.6':
+    resolution: {integrity: sha512-ru00MoyeeouE5BX4gRL+6m/BsDfbRayOskWqUvh7CLGW+UXxHQItqALa38kKnOiZPqJrtzJUgAC2+F0rL1S4Pg==}
+
   '@types/unist@2.0.11':
     resolution: {integrity: sha512-CmBKiL6NNo/OqgmMn95Fk9Whlp2mtvIv+KNpQKN2F4SjvrEesubTRWGYSg+BnWZOnlCaSTU1sMpsBOzgbYhnsA==}
 
@@ -15274,6 +15280,8 @@ snapshots:
   '@types/trusted-types@2.0.7':
     optional: true
 
+  '@types/turndown@5.0.6': {}
+
   '@types/unist@2.0.11': {}
 
   '@types/unist@3.0.2': {}