aura: Add configuration for Aura

As of now, aura does not support relative paths for cache
and related directories.
https://github.com/fosskers/aura/issues/937

aura/.config/aura/config.toml

@@ -0,0 +1,23 @@
+[aur]
+chroot        = []
+ignores       = []
+git           = true
+hotedit       = false
+shellcheck    = true
+diff          = true
+delmakedeps   = true
+clean         = true
+warn_unknowns = true
+nocheck       = false
+skipdepcheck  = false
+reverse       = false
+
+[backups]
+automatic     = false
+
+[general]
+cpus          = 4
+editor        = "nvim"
+doas          = true
+language      = "en-US"
+noconfirm     = false