Support sub-routers

[trestletech]

Plumber routers should be able to stack on one another by giving a prefix.

e.g.

prAcct <- plumb("accounts.R")
prSales <- plumb("sales.R")
pr$addRouter(prAcct, "/account")
pr$addRouter(prSales, "/sales")

[rauno56]

+1

Or a simple way to combine different files with routes would also help with structuring the code.
e.g.

prAcct <- plumb("accounts.R")
prBoth <- prAcct$combine(plumb("sales.R"))

[nihonjinrxs]

I'm fine with #60 being closed as a dup of this one, but do you have any timeline for implementation of this enhancement?

[ankur-gupta]

+1

All of these features would help us a lot to structure larger projects with lots of endpoints.
I would really appreciate this feature being available sooner. Thanks.