A Quarto filter extension that enables colspan and rowspan in Markdown tables.

Installing

quarto add herosi/table-cell-merge

This will install the extension under the _extensions subdirectory. If you're using version control, you will want to check in this directory.

Using

Add the following line to your .qmd file or _quarto.yaml to enable the extension.
```
filters:
  - { at: post-quarto, path: table-cell-merge }
```
Note: The extension must be loaded using the format shown above. Otherwise, it will not work with tbl-colwidths.
Add a line like the following after the table.
```
: {tbl-merge="[1:2:col:2, 2:1:row:3]"}
```

Key	Type	Value
row	integer	1-based row index (header rows first, then body rows)
col	integer	1-based column index
direction	string	`col` (for `colspan`) or `row` (for `rowspan`)
span	integer	number of cells to merge (>= 2)

The contents of merged cells are ignored; only the content of the leading cell is preserved.
When colspan and rowspan are specified together, the cells are merged into a rectangular region (following the HTML colspan/rowspan behavior).

Here is the source code for a minimal example: example.qmd. View an example presentation at example.html.