title: Pass Parameters from Command line into R markdown document
body: <p>I'm running a markdown report from command line via:</p>
  
  <p><code>R -e "rmarkdown::render('ReportUSV1.Rmd')"</code></p>
  
  <p>This report was done in R studio and the top looks like</p>
  
  <pre><code>---
  title: "My Title"
  author: "My Name"
  date: "July 14, 2015"
  output: 
    html_document:
     css: ./css/customStyles.css
  ---
  
  
  ```{r, echo=FALSE, message=FALSE}
  
  load(path\to\my\data)
  ```
  </code></pre>
  
  <p>What I want is to be able to pass in the title along with a file path into the shell command so that it generates me the raw report and the result is a different filename.html. </p>
  
  <p>Thanks!</p>