packages feed

pandoc-3.10: test/command/10884.md

```
% pandoc -f markdown -t markdown
  header1   header2
  --------- ---------
  r1c1      r1c2
  r2c1      r2c2

  : mycaption {#myid .myclass key="value"}
^D
  header1   header2
  --------- ---------
  r1c1      r1c2
  r2c1      r2c2

  : mycaption {#myid .myclass key="value"}

```