Improve the console output for quarto render

[cwickham]

An example of existing output:

$ quarto render html-r.qmd

processing file: html-r.qmd
1/5
2/5 [unnamed-chunk-1]
3/5
4/5 [unnamed-chunk-2]
5/5
output file: html-r.knit.md

pandoc
  to: html
  output-file: html-r.html
  standalone: true
  section-divs: true
  html-math-method: mathjax
  wrap: none
  default-image-extension: png

metadata
  document-css: false
  link-citations: true
  date-format: long
  lang: en
  title: My document
                                
Output created: html-r.html

For most users, most of the time, there is too much detail and not clear enough signposts on where Quarto is in the process.

An example, purely to promote discussion:

$ quarto render html-r.qmd
Engine: knitr
Formats: html

Format: html
-------------------------------------------
Executing code with knitr targeting HTML: 
[=======] 100% | 5/5
Intermediate file: html-r.html.md 

Converting to HTML with pandoc
Output created: html-r.html
-------------------------------------------