LF_CONFIG_HOME environment variable

[alok-mishra]

resolves #1209

@gokcehan, I am submitting this PR for #1209, to add LF_CONFIG_HOME as an option for Windows to be an alternative to LOCALAPPDATA so as to not affect other installed applications. I have not touched the Unix side yet as I didn't know if you wanted me to update that, but if you do, please let me know, and I'll add this there as well.

I have also added some documentation for LF_CONFIG_HOME, hopefully I did that properly, but please let me know if I need to format it differently.

Thank you

[ilyagr]

To edit the documentation, you should edit doc.go and then run go generate. That will overwrite docstring.go and also create the man page.

[alok-mishra]

Thanks for the clarification, I'll change it in doc.go

[alok-mishra]

@ilyagr , as per your instructions, I moved documentation to doc.go and used go generate to update docstring.go and lf.1

[gokcehan]

@alok-mishra Looks good, thanks for the patch.

I think it would make sense to also add this to unix to be consistent. However, I forgot windows does not have separate config and data folders, so if we want to add this to unix, I guess it should be somehow added as two variables, LF_CONFIG_HOME and LF_DATA_HOME as mentioned in #1209. I can merge this PR as it is and change it later myself if you don't want to bother.

[alok-mishra]

@gokcehan Sure, I am happy to do that also, was just making sure that it was wanted on unix side. I'll add LF_CONFIG_HOME LF_DATA_HOME and you also mentioned LF_RUNTIME_DIR in #1209.

Yes, please go ahead and merge this PR, and I'll submit another for those changes soon!

[gokcehan]

@alok-mishra Thanks for the patch.