; Add face customization to ERC's sample config

; Add face customization to ERC's sample config

* doc/misc/erc.texi (Sample Configuration): Move `erc-modules' twiddling
from a `use-package' :config section to a :custom section.  In the past,
this would sometimes provoke module-loading issues, but it seems to work
fine on Emacs 30, even with repeated eval'ing of the `use-package' form.
This sample config is meant for users running the latest release anyhow.
Also add a new `use-package' block for `erc-match' showing how to
customize a face using inheritance.  Add a corresponding section further
down showing the same via Customize.

(cherry picked from commit 3f1ce47fe7eb4809bfa9ef035caae748c3c5d729)