Nudge new users towards using this style:
```lua
local config = {}
config.color_scheme = 'Batman'
return config
```
and surface how to write lua modules closer to the main section
on config files. In that lua modules section, nudge towards using
a convention similar to that of the plugin spec described in
this commit: e4ae8a844d
Migrate information into the relevant config option pages, and
instead summarize with a demonstration of configuring the font.
For wezterm.font, there's now an expanded discussion on naming
and matching fonts.
closes: https://github.com/wez/wezterm/issues/560
