title: Using mathjaxr to get nice display in r package documentation
body: <p>I'm having difficulties with the mathjaxr package to get nice display in the documentation of <strong>my first package</strong>.</p>
  <p>I followed instructions given here : <a href="https://rdrr.io/github/wviechtb/mathjaxr/man/mathjaxr-package.html" rel="nofollow noreferrer">https://rdrr.io/github/wviechtb/mathjaxr/man/mathjaxr-package.html</a></p>
  <p>Here is what I put in my R file before the function :</p>
  <pre><code>#' Probabilistic principal component analysis :
  #' parameter estimation with EM algorithm
  #'
  #' @param Y les données : une matrice de taille n x p
  #' @param Gamma0 point de départ pour l'inférence de Gamma
  #'
  #' @return la fonction renvoie la moyenne d'un vecteur
  #' @import mvtnorm
  #' @import psych
  #' @import mathjaxr
  #' @description 
  #' \loadmathjax
  #' \mjdeqn{f(x) = \frac{1}{\sqrt{2\pi} \sigma} e^{-\frac{1}{2}\left(\frac{x-\mu}{\sigma}#\right)^2},}
  #' {f(x) = 1/(sqrt(2 pi) sigma) e^-((x - mu)^2/(2 sigma^2)),}
  </code></pre>
  <p>And here is what I have in my description file :</p>
  <pre><code>Package: ppcaem
  Title: Parameter estimation in ppca model with EM algorithm
  Version: 0.0.0.9000
  Authors@R: 
      person(given = &quot;First&quot;,
             family = &quot;Last&quot;,
             role = c(&quot;aut&quot;, &quot;cre&quot;),
             email = &quot;first.last@example.com&quot;,
             comment = c(ORCID = &quot;YOUR-ORCID-ID&quot;))
  Description: cf title
  RdMacros: mathjaxr
  License: GPL-3
  Encoding: UTF-8
  LazyData: true
  Imports: 
      psych,
      mvtnorm,
      mathjaxr
  RoxygenNote: 7.1.1
  </code></pre>
  <p>And here is the rendered :</p>
  <p><a href="https://i.stack.imgur.com/Dlf5a.png" rel="nofollow noreferrer">mathjaxr</a></p>