title: Generate beautiful summary table output for lmer models in R Markdown?
body: <p>I have a lot of lmer models with a <code>summary()</code> output that looks like this (usually with more variables, this was just a very quick nonsense example I generated):</p>
  <pre><code>Linear mixed model fit by REML. t-tests use Satterthwaite's method ['lmerModLmerTest']
  Formula: mpg ~ cyl + hp + disp * drat + (1 | gear) + (1 | carb)
     Data: mtcars
  
  REML criterion at convergence: 171.8
  
  Scaled residuals: 
      Min      1Q  Median      3Q     Max 
  -1.4583 -0.5671 -0.2118  0.3912  2.1303 
  
  Random effects:
   Groups   Name        Variance Std.Dev.
   carb     (Intercept) 2.07353  1.4400  
   gear     (Intercept) 0.04659  0.2158  
   Residual             7.63829  2.7637  
  Number of obs: 32, groups:  carb, 6; gear, 3
  
  Fixed effects:
              Estimate Std. Error       df t value Pr(&gt;|t|)  
  (Intercept)  6.27454   11.75344 25.17470   0.534   0.5981  
  cyl         -0.30519    0.84443 25.55852  -0.361   0.7208  
  hp          -0.01412    0.01798 10.10227  -0.785   0.4503  
  disp         0.03101    0.03649 23.25810   0.850   0.4041  
  drat         5.97395    2.65430 24.44199   2.251   0.0337 *
  disp:drat   -0.01380    0.01172 24.05299  -1.178   0.2503  
  ---
  Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
  
  Correlation of Fixed Effects:
            (Intr) cyl    hp     disp   drat  
  cyl       -0.512                            
  hp        -0.087 -0.337                     
  disp      -0.710 -0.021  0.341              
  drat      -0.965  0.317  0.142  0.823       
  disp:drat  0.698 -0.131 -0.461 -0.950 -0.778
  convergence code: 0
  Model failed to converge with max|grad| = 0.0112263 (tol = 0.002, component 1)
  </code></pre>
  <p>Is there a way to generate a <code>summary()</code> output with all of this information, but nicely formatted for RMarkdown? I've found a variety of solutions for Markdown (e.g. <code>kable</code>, <code>huxtable</code>, <code>pander</code>), but most of them are only able to display for example the Fixed Effects table. In those examples, the Signif. codes stars (<code>*</code>-<code>***</code>) are usually also not shown.</p>
  <p>I'm looking for a function that gives me an output just like this, but formatted for RMarkdown and including the significance codes.</p>