Excel structure for title_footer_decorator

# Excel structure for `title_footer_decorator`

This vignette documents the exact structure expected by `title_footer_decorator()` for the Excel specification file. The decorator expects a sheet that lists table identifiers and, for each table, a `TITLE` row and zero or more `FOOTNOTE` rows.

The function expects the titles to be in the first sheet named `Sheet1`. The column names must be the first row of the file (i.e. `TABLE ID`, `IDENTIFIER`, `TEXT`).

Below is an example of a table that would work for the decorator. The `DO_NOT_DELETE` values in the first row are intentional and have to be part of the file.

    example_excel <- data.frame(
      `TABLE ID` = c(
        "DO_NOT_DELETE",
        "TSFAE01A", "TSFAE01A", "TSFAE01A", "TSFAE01A", "TSFAE01A", "TSFAE01A", "TSFAE01A",
        "TSFAE01B", "TSFAE01B", "TSFAE01B", "TSFAE01B", "TSFAE01B", "TSFAE01B", "TSFAE01B"
      ),
      IDENTIFIER = c(
        "DO_NOT_DELETE",
        "TITLE", "FOOTNOTE1", "FOOTNOTE2", "FOOTNOTE3", "FOOTNOTE4", "FOOTNOTE5", "FOOTNOTE6",
        "TITLE", "FOOTNOTE1", "FOOTNOTE2", "FOOTNOTE3", "FOOTNOTE4", "FOOTNOTE5", "FOOTNOTE6"
      ),
      TEXT = c(
        "DO_NOT_DELETE",
        "Some title", "First part of footnote", "Another part of footnote", "Another part of footnote",
        "Another part of footnote", "Another part of footnote", "Another part of footnote",
        "Some title", "First part of footnote", "Another part of footnote", "Another part of footnote",
        "Another part of footnote", "Another part of footnote", "Another part of footnote"
      ),
      stringsAsFactors = FALSE,
      check.names = FALSE
    )

    knitr::kable(example_excel)

TABLE ID | IDENTIFIER | TEXT
--- | --- | ---
DO_NOT_DELETE | DO_NOT_DELETE | DO_NOT_DELETE
TSFAE01A | TITLE | Some title
TSFAE01A | FOOTNOTE1 | First part of footnote
TSFAE01A | FOOTNOTE2 | Another part of footnote
TSFAE01A | FOOTNOTE3 | Another part of footnote
TSFAE01A | FOOTNOTE4 | Another part of footnote
TSFAE01A | FOOTNOTE5 | Another part of footnote
TSFAE01A | FOOTNOTE6 | Another part of footnote
TSFAE01B | TITLE | Some title
TSFAE01B | FOOTNOTE1 | First part of footnote
TSFAE01B | FOOTNOTE2 | Another part of footnote
TSFAE01B | FOOTNOTE3 | Another part of footnote
TSFAE01B | FOOTNOTE4 | Another part of footnote
TSFAE01B | FOOTNOTE5 | Another part of footnote
TSFAE01B | FOOTNOTE6 | Another part of footnote