In jread-usgs/dinosvg: Create dynamic SVGs from scratch

`dinosvg` package version `r packageVersion('dinosvg')`

purpose of package

dinsvg is a work in progress, but is designed to support structured svg output from the gsplot package. The package also has a few annotation pieces built in, limited right now to hovertext.

rendering svgs

create a plot with gsplot

library(gsplot)
gs <- gsplot() %>% 
  points(y=1:11, x=1:11, 
           col="blue", pch=18, xlab='pizza', ylab='dogs') %>% 
  points(x=4:11, y=11:4, 
           col="red", pch=1) %>% 
  points(3:5,4:6,side=c(1,4), col='green', pch=14, ylab='cats') %>% 
  lines(2:4, c(2,2.6,2.3), col='blue')
gs

library(dinosvg)
gs <- gsplot() %>% 
  points(y=1:11, x=1:11, 
           col="blue", pch=18, hovertext=paste0('text:',1:11), xlab='pizza', ylab='dogs', 
           id=paste0('point',1:11), 'fill-opacity'='0.3', 'stroke-opacity'=seq(0,1, length.out = 11)) %>% 
  points(x=4:11, y=11:4, 
           col="red", pch=1, hovertext=paste0('text:',11:4)) %>% 
  points(3:5,4:6,side=c(1,4), col='green', hovertext='green', pch=14, ylab='cats') %>% 
  lines(2:4, c(2,2.6,2.3), col='blue')
cat('```xml\n',svg(gs, as.string=TRUE),'\n```')