tre: add livecheck and license (#107808)
tre: add livecheck and license (#107808)

License taken from https://laurikari.net/tre/download.
lemzwerg/homebrew-core,filcab/homebrew-core,sjackman/homebrew-core,makigumo/homebrew-core,Homebrew/homebrew-core,stgraber/homebrew-core,chrisfinazzo/homebrew-core,makigumo/homebrew-core,chrisfinazzo/homebrew-core,lemzwerg/homebrew-core,Homebrew/homebrew-core,nandub/homebrew-core,filcab/homebrew-core,adam-moss/homebrew-core,nandub/homebrew-core,sjackman/homebrew-core,stgraber/homebrew-core,adam-moss/homebrew-core