title: Insert Youtube link if link exists in R
body: <p>I have this tibble:</p>
  
  <pre><code>structure(list(stem = "In what place was Christmas once illegal?", 
      img_vid = "Enter Link", correct = "Russia", d1 = "Brazil", 
      d2 = "England", d3 = "France", exp = "Enter Explanation", 
      exp_img_vid = "Enter Link"), row.names = c(NA, -1L), class = c("tbl_df", 
  "tbl", "data.frame"), spec = structure(list(cols = list(stem = structure(list(), class = c("collector_character", 
  "collector")), img_vid = structure(list(), class = c("collector_character", 
  "collector")), correct = structure(list(), class = c("collector_character", 
  "collector")), d1 = structure(list(), class = c("collector_character", 
  "collector")), d2 = structure(list(), class = c("collector_character", 
  "collector")), d3 = structure(list(), class = c("collector_character", 
  "collector")), exp = structure(list(), class = c("collector_character", 
  "collector")), exp_img_vid = structure(list(), class = c("collector_character", 
  "collector"))), default = structure(list(), class = c("collector_guess", 
  "collector"))), class = "col_spec"))
  </code></pre>
  
  <p>I'd like to embed a Youtube video inside a RMarkdown if the link for the video exists in the columns <code>img_vid</code> and <code>exp_img_vid</code> . </p>
  
  <p>I was thinking of using <code>if</code> statements, but how would I do so if the syntax for embedding links is<br>
  <code>![Video Title](Video Link)</code></p>
  
  <p>Thanks,</p>