Add pkgdown html to site articles generated by rmarkdown::render()

Question

I'm hoping to use pkgdown to generate analysis websites and would like to use a large object in multiple site articles without either re-computing or saving a .Rda file to include with the package build (i.e., data/x.Rda).

By default, pkgdown::build_site() ignores files in the vignettes subdirectory with preceding underscores. My current approach uses a file vignettes/articles.Rmd to perform some calculations that generate a large object, then renders additional .html files using this global object via calls to rmarkdown::render(). The contents of the .Rmd look something like this:

---
title: "Render Articles"
---

Would like to be able to share `x` with reports and maintain pkgdown html.

```{r}
x <- runif(n = 10000000) # Some calculations that generate a large object
```

Global object `x` is available from `_QC1.Rmd`

```{r}
# Code chunk to generate report (repeated for multiple _*.Rmd files)
rmarkdown::render(
  input = "_QC1.Rmd",  # pkgdown::build_site() ignores files with preceding underscore
  output_file = "QC1.html"  # renders HTML file output without "_"; copied to docs/articles/
)
```

The _pkgdown.yml can be modified to pickup the html files rendered from the Rmarkdown reports, but they lose the site formatting that is automated for other .Rmd files by pkgdown::build_site().

I'd like to include the pkgdown site html formatting (i.e., title and site navbar) in these Rmarkdown reports if possible.

_pkgdown.yml contents:

navbar:
  title: ~
  left:
    - text: QC
      menu:
        - text: QC1
          href: articles/QC1.html
        - text: QC2
          href: articles/QC2.html

I'm unsure if there is a better way for sharing an object across articles (though I understand these are typically self-contained). This approach works, but the html pages rendered for the Rmarkdown reports lose pkgdown formatting which drops the site navbar.

# Example of package vignettes subdirectory contents
1 vignettes
2  ¦--_QC1.Rmd  # ignored by pkgdown::build_site()
3  ¦--_QC2.Rmd
4  ¦--articles.html 
5  ¦--articles.Rmd  # contains R chunks for rendering Rmarkdown reports
6  ¦--QC1.html  # picked up in _pkgdown.yml from `docs/articles/`
7  °--QC2.html

Edit: Will look into the source code here:

https://github.com/r-lib/pkgdown/blob/master/R/build-articles.R