Add automatic shellchecks with CI

Signed-off-by: Reed Wade <reedwade@misterbanal.net>

.build.yml

@@ -0,0 +1,9 @@
+image: alpine/edge
+packages:
+  - shellcheck
+sources:
+  - https://git.sr.ht/~mil/sxmo-utils
+tasks:
+  - shellcheck: |
+      cd sxmo-utils
+      shellcheck scripts/*/*

scripts/core/sxmo_xinit.sh

@@ -3,6 +3,7 @@
 envvars() {
 	# shellcheck disable=SC1091
 	[ -f /etc/profile ] && . /etc/profile
+	# shellcheck source=/dev/null
 	[ -f "$HOME"/.profile ] && . "$HOME"/.profile
 	command -v "$TERM" || export TERM=st
 	command -v "$BROWSER" || export BROWSER=surf