Doom's package help uses `git grep` to search for files in Doom
configuring a package, which does not work for us because our Doom
install does not live in a Git checkout. Unfortunately this breaks
package help completely because of error handling problems.
Add advice to use ripgrep instead, which fixes package help.
I don't like doing this: I've sent the same fix upstream, if it's not
accepted there I may just make Doom in the Nix store be a Git checkout.
Add an (empty) straight.el build cache to the generated profile, and
load it when Doom calls `doom-initialize-core-packages` (which normally
does so by side effect).
Unfortunately requires adding to pre-init: Doom overrides
`straight-base-dir`, and we need to override that override.
Partially fixes package help.
...by moving the existing hack from the CLI to init.el.
It's not really necessary to do this as early as init.el, but I'm coming
around to using init.el modifications as an alternative to using Doom's
profile loader. So we might as well do this in the same place.
This is not sufficient to make doom/help-packages work, but gets us one
step closer...
