docs(README): document neovim colorscheme generation

README.md

@@ -496,6 +496,8 @@ vim.api.nvim_command 'colorscheme <name>'
 
 This plugin has the ability to export _any_ colorscheme (not just ours!) to various formats, including:
 
+* Neovim Lua theme
+    * NOTE: this particular exporter has special functionality. Since exporting requires an input colorscheme, you can create a `colors/.foo.vim`/`lua` file, and the leading `.` will be stripped. For example, `colors/.foo.lua` will become `colors/foo.lua`. This way, you can continually bootstrap generation of a custom colorscheme into a standalone colorscheme without the source file standing out.
 * `wezterm` theme
 
 To make use of this, just run this after installing the plugin:

doc/highlite.txt

@@ -375,6 +375,8 @@ This plugin has the ability to export _any_ colorscheme (not just ours!) to
 various formats, including:
 
 
+- Neovim Lua theme
+    - NOTE: this particular exporter has special functionality. Since exporting requires an input colorscheme, you can create a `colors/.foo.vim`/`lua` file, and the leading `.` will be stripped. For example, `colors/.foo.lua` will become `colors/foo.lua`. This way, you can continually bootstrap generation of a custom colorscheme into a standalone colorscheme without the source file standing out.
 - `wezterm` theme
 
 To make use of this, just run this after installing the plugin:
@@ -1365,6 +1367,61 @@ FEATURES                                                   *highlite-features*
 This section is about contributing new features to `nvim-highlite`.
 
 
+EXPORT TARGETS ~
+
+`nvim-highlite` has an internal string formatting library that allows you to
+easily write a template for whatever you need, and all the logic will be
+handled behind the scenes:
+
+>lua
+    function Fmt.string(format: string, opts?: highlite.Fmt.string.opts)
+      -> formatted: string, count: integer
+<
+
+The `opts` are as follows:
+
+>lua
+    --- @class highlite.Fmt.string.opts
+    --- @field convert_int_attributes? false|'hex_literal'|'hex_string' if `Foo.bar` is an integer (e.g. when `Normal.fg == 16777215`), convert it to a hex string (e.g. `'#FFFFFF'`) or a hex literal (e.g. `0xFFFFFF`)
+    --- @field default? true|{[string]: highlite.Fmt.string.substitution} if `true`, use default values when formatting returns `nil` for a highlight group
+    --- @field loadstring_compat? boolean if `true`, enable compatability for `loadstring`ing the returned value
+    --- @field map? fun(attribute: string, value: highlite.Fmt.string.substitution): highlite.Fmt.string.substitution
+    local FMT_STRING_DEFUALT_OPTS = {
+      convert_int_attributes = 'hex_string',
+      default = true,
+    }
+<
+
+For example, you can do this:
+
+>lua
+    local Fmt = require 'highlite.fmt' --- @type highlite.Fmt
+    local formatted = Fmt.string [[
+    normal_bg = ${Normal.bg}
+    fallback_bg = ${undefined_group.bg | defined_group.underline}
+    terminal_idx_1 = ${1}
+    ]]
+<
+
+
+- The `Import` <../lua/highlite/import.lua> and `Export` <../lua/highlite/export.lua> modules have more examples.
+
+The `Fs` <../lua/highlite/fs.lua> module will be of use for writing the end
+result.
+
+
+IMPORT TARGETS ~
+
+Depending on the format, you might have to write a custom parser. Neovim
+supports JSON with `vim.json`, Lua can be read with `loadstring`, and VimScript
+can be parsed with `nvim_parse_expression`.
+
+Considering the open-ended nature of this topic, open an issue if you have
+trouble working on what you would like to do.
+
+The `Fs` <../lua/highlite/fs.lua> module might be of interest.
+
+
 PALETTES ~