update README with badge links to Dockerfiles

README.md

@@ -8,10 +8,10 @@
 
 image            | description                               | tags 
 ---------------- | ----------------------------------------  | ---- 
-r-ver:3.3.2      |  Version-stable base R & src build tools  | [![](https://images.microbadger.com/badges/image/rocker/r-ver.svg)](https://microbadger.com/images/rocker/r-ver "Get your own image badge on microbadger.com")  
-rstudio:3.3.2    |  Adds rstudio                             | [![](https://images.microbadger.com/badges/image/cboettig/rstudio.svg)](https://microbadger.com/)  
-tidyverse:3.3.2  |  Adds tidyverse & devtools                | [![](https://images.microbadger.com/badges/image/rocker/tidyverse.svg)](https://microbadger.com/images/rocker/tidyverse "Get your own image badge on microbadger.com")  
-verse:3.3.2      |  Adds tex & publishing-related packages   | [![](https://images.microbadger.com/badges/image/rocker/verse.svg)](https://microbadger.com/images/rocker/verse "Get your own image badge on microbadger.com")  
+r-ver:3.3.2      |  Version-stable base R & src build tools  | [![](https://images.microbadger.com/badges/image/rocker/r-ver.svg)](https://microbadger.com/images/rocker/r-ver) [![](https://img.shields.io/badge/Dockerfile-v3.3.2-blue.svg)](https://github.com/rocker-org/rocker-versioned/blob/master/r-ver/3.3.2/Dockerfile)  
+rstudio:3.3.2    |  Adds rstudio                             | [![](https://images.microbadger.com/badges/image/cboettig/rstudio.svg)](https://microbadger.com/) [![](https://img.shields.io/badge/Dockerfile-v3.3.2-blue.svg)](https://github.com/rocker-org/rocker/blob/master/rstudio/3.3.2/Dockerfile)  
+tidyverse:3.3.2  |  Adds tidyverse & devtools                | [![](https://images.microbadger.com/badges/image/rocker/tidyverse.svg)](https://microbadger.com/images/rocker/tidyverse) [![](https://img.shields.io/badge/Dockerfile-v3.3.2-blue.svg)](https://github.com/rocker-org/rocker-versioned/blob/master/tidyverse/3.3.2/Dockerfile)  
+verse:3.3.2      |  Adds tex & publishing-related packages   | [![](https://images.microbadger.com/badges/image/rocker/verse.svg)](https://microbadger.com/images/rocker/verse) [![](https://img.shields.io/badge/Dockerfile-v3.3.2-blue.svg)](https://github.com/rocker-org/rocker-versioned/blob/master/verse/3.3.2/Dockerfile)  
 
 
 Notes