refactor(users/glittershark): Rename to grfn

Rename my //users directory and all places that refer to glittershark to
grfn, including nix references and documentation.

This may require some extra attention inside of gerrit's database after
it lands to allow me to actually push things.

Change-Id: I4728b7ec2c60024392c1c1fa6e0d4a59b3e266fa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2933
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
Reviewed-by: lukegb <lukegb@tvl.fyi>
Reviewed-by: glittershark <grfn@gws.fyi>

users/grfn/resume/helvetica.sty

@@ -0,0 +1,32 @@
+%% 
+%% This is file `helvetica.sty', based on helvet.sty extended to include 
+%% definitions for rm and tt.  This means commands such as \textbf, \textit,
+%% etc. will appear in Helvetica.  
+%% Changes added by Harriet Borton on <1995/12/11> 
+%% 
+%% The original source files were:
+%% 
+%% psfonts.dtx  (with options: `helvet')
+%% 
+%% Copyright (C) 1994 Sebastian Rahtz 
+%% All rights reserved. 
+%% 
+%% The original file is part of the PSNFSS2e package. 
+%% ----------------------------------------- 
+%% 
+%% This is a generated file. Permission is granted to to customize the 
+%% declarations in this file to serve the needs of your installation. 
+%% However, no permission is granted to distribute a modified version of 
+%% this file under its original name. 
+\def\fileversion{4.2}
+\def\filedate{94/11/11}
+\def\docdate {94/11/06}
+\NeedsTeXFormat{LaTeX2e}
+\ProvidesPackage{helvetica}[\filedate\space\fileversion\space
+Helvetica PSNFSS2e package]
+\renewcommand{\sfdefault}{phv}
+\renewcommand{\rmdefault}{phv}
+\renewcommand{\ttdefault}{pcr}
+\endinput
+%% 
+%% End of file `helvetica.sty'.