Print method for the yaml_header class

# S3 method for rmd_yaml_header
print(x, ...)

input <- list(author = "", output = "pdf_document", toc = TRUE, keep_tex = TRUE)
out <- as_yaml_auto(input)
out
#> ---
#> author: ''
#> output:
#>   pdf_document:
#>     toc: yes
#>     keep_tex: yes
#> ---
print(out)
#> ---
#> author: ''
#> output:
#>   pdf_document:
#>     toc: yes
#>     keep_tex: yes
#> ---