Add R highlighting from RStudio (plus other dependencies)

demo/kitchen-sink/docs/r.r

@@ -0,0 +1,20 @@
+Call:
+lm(formula = y ~ x)
+ 
+Residuals:
+1       2       3       4       5       6
+3.3333 -0.6667 -2.6667 -2.6667 -0.6667  3.3333
+ 
+Coefficients:
+            Estimate Std. Error t value Pr(>|t|)
+(Intercept)  -9.3333     2.8441  -3.282 0.030453 *
+x             7.0000     0.7303   9.585 0.000662 ***
+---
+Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
+ 
+Residual standard error: 3.055 on 4 degrees of freedom
+Multiple R-squared: 0.9583,     Adjusted R-squared: 0.9478
+F-statistic: 91.88 on 1 and 4 DF,  p-value: 0.000662
+ 
+> par(mfrow=c(2, 2))     # Request 2x2 plot layout
+> plot(lm_1)             # Diagnostic plot of regression model