enable shellcheck

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I15d9134d8deab0bdb5b79cee81ef06e06f59b9a6
diff --git a/.shellcheck b/.shellcheck
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/.shellcheck