Adding support for another Package Manager to Forage

Note: This document isn't quite finished yet!

functions to implement

importLatest
importPackage
verify
watchImporter
updatePackage
serverHandler
isLockfilepath
readLockfile
lockfileExists
lockfileName
watchKnown
setConfig
unsetConfig
setupWatcher
matchesUseragent
versionAsJson
packageAsJson
importMetadata
downloadVersion