add hotswap to the norns lib

[jaseknighter]

issue: hotswap is missing from the norns lib. i will submit a pull request for this and i believe no changes are required to the code.

fix: copy crow hotswap.lua file to the norns /lib directory.

testing: after making this change and restarting my norns, i tested from the maiden repl using the code from the crow hotswap documentation:

sequins = require('sequins')
hotswap = require('hotswap')
-- the sequins is overwritten, but the playhead is preserved
hotswap.seq = sequins{1,2,3}
hotswap.seq() --> 1
hotswap.seq() --> 2
hotswap.seq = sequins{4,5,6,7}
hotswap.seq() --> 6