feat: Add template.json files for all templates

[gadenbuie]

For posit-dev/py-shiny#1631 but can be merged at any time. I'm going to wait to merge this when we also update py-shiny-site or at least closer to the next py-shiny release. The updated shiny create workflow removes the _template.json files, but they will not be removed by older versions of shiny.

• Related: fix: retitle basic-sidebar template py-shiny-site#204
• Merge with: Update shiny create calls for Shiny v1.1.0 py-shiny-site#209

Create template.json

library(fs)
library(rvest)

apps <- dir_ls(".", recurse = TRUE, glob = "**/app-*.py")
apps <- apps[!grepl("venv", apps)]

for (app in apps) {
  tmpl_json <- path(path_dir(app), "_template.json")
  if (file_exists(tmpl_json)) {
    next
  }

  slug <- path_file(path_dir(app))
  cli::cli_progress_step(slug)
  
  title <- ""
  description <- ""
  tryCatch({
    url <- glue::glue("https://shiny.posit.co/py/templates/{slug}/")
    page <- read_html(url)
  
    title <- page %>% html_node("h1") %>% html_text()
    description <- page %>% html_node(".panel-tabset + p") %>% html_text()
    description <- paste0(strsplit(description, "[.] [A-Z]")[[1]][1], ".")
  }, error = function(err) {
    cli::cli_inform("Failed to scrape template info for {slug}.")
  })

  template <- list(
    name = slug,
    title = title,
    description = description
  )

  jsonlite::write_json(template, tmpl_json, pretty = TRUE, auto_unbox = TRUE)
}

cli::cli_progress_done()