features: envs.GetFirst{,WithRef}, paths.GetFirst{,WithRef}

TODO

@@ -2,12 +2,24 @@
 -- incorporate with https://github.com/tredoe/osutil ?
 -- cli flag to dump flat hashes too
 --- https://github.com/hlandau/passlib
+-- incoprporated separately; https://git.r00t2.io/r00t2/PWGen (import r00t2.io/pwgen)
 
 - unit tests
 
 - constants/vars for errors
 
 - func and struct to return segregated system-level env vars vs. user env vars (mostly usable on windows) (see envs/.TODO.go.UNFINISHED)
+-- https://www3.ntu.edu.sg/home/ehchua/programming/howto/Environment_Variables.html
+-- windows:
+--- https://docs.microsoft.com/en-us/windows/deployment/usmt/usmt-recognized-environment-variables
+--- https://pureinfotech.com/list-environment-variables-windows-10/
+--- https://gist.github.com/RebeccaWhit3/5dad8627b8227142e1bea432db3f8824
+--- https://ss64.com/nt/syntax-variables.html
+-- linux/XDG:
+--- https://pubs.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap08.html
+--- https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
+-- macOS:
+--- https://ss64.com/osx/syntax-env_vars.html
 
 - validator for windows usernames, domains, etc. (for *NIX, https://unix.stackexchange.com/a/435120/284004)
 -- https://docs.microsoft.com/en-us/troubleshoot/windows-server/identity/naming-conventions-for-computer-domain-site-ou