R: Vignettes and other documentation

# Vignettes and other documentation

## Vignettes from package 'blockr.core'

blockr.core::blocks-registry |  | 3. Browse for blocks | HTML | source | R code
blockr.core::create-block |  | 2. Create a block | HTML | source | R code
blockr.core::extend-blockr |  | 4. Extend blockr | HTML | source | R code
blockr.core::get-started |  | 1. Getting started | HTML | source | R code
blockr.core::testing-blocks |  | 5. Testing blocks | HTML | source | R code