fix(lib): update doom/set-indent-width for dtrt-indent
fix(lib): update doom/set-indent-width for dtrt-indent

dtrt-indent-hook-mapping-list entries now accept lists of variables.
This updates doom/set-indent-width to accommodate that.

Ref: 95738859125c5343fd268390333ce599f9e0fc6d@1986ad4e60f2

hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs