Add license info

LICENSE.zsh

@@ -0,0 +1,26 @@
+The Z Shell is copyright (c) 1992-2017 Paul Falstad, Richard Coleman,
+Zoltán Hidvégi, Andrew Main, Peter Stephenson, Sven Wischnowsky, and
+others.  All rights reserved.  Individual authors, whether or not
+specifically named, retain copyright in all changes; in what follows, they
+are referred to as `the Zsh Development Group'.  This is for convenience
+only and this body has no legal status.  The Z shell is distributed under
+the following licence; any provisions made in individual files take
+precedence.
+
+Permission is hereby granted, without written agreement and without
+licence or royalty fees, to use, copy, modify, and distribute this
+software and to distribute modified versions of this software for any
+purpose, provided that the above copyright notice and the following
+two paragraphs appear in all copies of this software.
+
+In no event shall the Zsh Development Group be liable to any party for
+direct, indirect, special, incidental, or consequential damages arising out
+of the use of this software and its documentation, even if the Zsh
+Development Group have been advised of the possibility of such damage.
+
+The Zsh Development Group specifically disclaim any warranties, including,
+but not limited to, the implied warranties of merchantability and fitness
+for a particular purpose.  The software provided hereunder is on an "as is"
+basis, and the Zsh Development Group have no obligation to provide
+maintenance, support, updates, enhancements, or modifications.
+

README.md

@@ -136,3 +136,28 @@ zstyle ':completion:*:*:*:*:descriptions' format '%F{green}-- %d --%f'
 zstyle ':completion:*:messages' format ' %F{purple} -- %d --%f'
 zstyle ':completion:*:warnings' format ' %F{red}-- no matches found --%f'
 ```
+
+## LICENSES
+
+### Golang (BSD)
+
+Much of this code was forked from the official go source which is under the BSD
+license. The license preamble is retained in all files containing original or
+modified source from Go. LICENSE.golang is the LICENSE file distributed with Go.
+
+### Zsh (MIT)
+The Zsh completion script was adapted from the Zsh Users
+[zsh-completions](https://github.com/zsh-users/zsh-completions/blob/756831c818a8724f23b6c9ba08ae990854c62881/src/_golang)
+repo. This repo is under the Zsh license, which is MIT, but the itself script
+appears to be under the Go license. In any case LICENSE.zsh contains the Zsh
+license.
+
+### External Vendored Go Dependencies
+All non-Google external dependencies are MIT. Other Google dependencies are
+BSD-3. See licenses.csv for a full CSV report as generated by
+[go-licenses](https://github.com/google/go-licenses).
+
+### My code (MIT)
+
+Everything else that I wrote not directly modified from official Go source can
+be assumed to be under the MIT license.

licenses.csv

@@ -0,0 +1,21 @@
+aslevy.com/go-doc,Unknown,BSD-3-Clause
+github.com/alecthomas/chroma/v2,Unknown,MIT
+github.com/aymanbagabas/go-osc52,https://github.com/aymanbagabas/go-osc52/blob/v1.2.1/LICENSE,MIT
+github.com/aymerick/douceur,https://github.com/aymerick/douceur/blob/v0.2.0/LICENSE,MIT
+github.com/charmbracelet/glamour,Unknown,MIT
+github.com/dlclark/regexp2,https://github.com/dlclark/regexp2/blob/v1.7.0/LICENSE,MIT
+github.com/gorilla/css/scanner,https://github.com/gorilla/css/blob/v1.0.0/LICENSE,BSD-3-Clause
+github.com/lucasb-eyer/go-colorful,https://github.com/lucasb-eyer/go-colorful/blob/v1.2.0/LICENSE,MIT
+github.com/mattn/go-isatty,https://github.com/mattn/go-isatty/blob/v0.0.16/LICENSE,MIT
+github.com/mattn/go-runewidth,https://github.com/mattn/go-runewidth/blob/v0.0.14/LICENSE,MIT
+github.com/microcosm-cc/bluemonday,https://github.com/microcosm-cc/bluemonday/blob/v1.0.21/LICENSE.md,BSD-3-Clause
+github.com/muesli/reflow,https://github.com/muesli/reflow/blob/v0.3.0/LICENSE,MIT
+github.com/muesli/termenv,https://github.com/muesli/termenv/blob/v0.13.0/LICENSE,MIT
+github.com/olekukonko/tablewriter,https://github.com/olekukonko/tablewriter/blob/v0.0.5/LICENSE.md,MIT
+github.com/rivo/uniseg,https://github.com/rivo/uniseg/blob/v0.4.3/LICENSE.txt,MIT
+github.com/yuin/goldmark,https://github.com/yuin/goldmark/blob/v1.5.3/LICENSE,MIT
+github.com/yuin/goldmark-emoji,https://github.com/yuin/goldmark-emoji/blob/v1.0.1/LICENSE,MIT
+golang.org/x/exp,https://cs.opensource.google/go/x/exp/+/0915cd71:LICENSE,BSD-3-Clause
+golang.org/x/mod/semver,https://cs.opensource.google/go/x/mod/+/v0.6.0:LICENSE,BSD-3-Clause
+golang.org/x/net/html,https://cs.opensource.google/go/x/net/+/v0.4.0:LICENSE,BSD-3-Clause
+golang.org/x/sys/unix,https://cs.opensource.google/go/x/sys/+/v0.3.0:LICENSE,BSD-3-Clause